Teaching Chemical Information:
Tips and Techniques

— August 1998 —

Chemical Literature (Chem 184/284)
University of California at Santa Barbara

Lecture 3: Locating Books in the UCSB Library: PEGASUS & MELVYL

Arrangement of Materials

• Nearly all books and journals in the UCSB Library are arranged by call number, so that materials on related subjects will be grouped together.
• The UCSB Library follows the Library of Congress classification system.
  • The first group of letters signifies the broad subject area.
  • The first group of numbers signifies the more specific subject area.
  • The subsequent letters and numbers identify the individual book, and are usually based on the author's name and/or book's title.
• “Traditional” subject areas are well grouped:
  • QD = chemistry
  • QD 241-449 = organic chemistry
  • QD 380-388 = organic polymer chemistry
  • QD 410-413 = organometallic chemistry
  • QD 415-449 = biological chemistry
• Other “new” or “interdisciplinary” areas may be more scattered. For example, works containing chemical toxicity information may be found in:
  • GE = environmental science
  • QP = biochemistry & physiology
  • RA includes medical toxicology
  • S includes pesticide toxicology
  • T includes general toxic chemical data
  • TD = environmental engineering

Finding Call Numbers

• Libraries use catalogs to enable location of items by author, title or subject.
• UCSB has two electronic catalogs:
  • MELVYL, the UC-wide catalog system, and
  • PEGASUS, UCSB's catalog and circulation system.
  • Each has its advantages and disadvantages, depending on the type of search you need to do.

MELVYL and PEGASUS: Comparative Commands

• Author (Books)
  • MEL> f pa lastname, first
    Example: f pa pauling, linus
  • PEG> a lastname, first
    Example: a pauling, linus
• Full Title (books)
  • MEL> f xt title of the book
    Example: f xt the nature of the chemical bond
  • PEG> t title of the book
    Example: t nature of the chemical bond
  • Note that both systems automatically truncate the end of exact title searches, and that you must omit initial articles (a, an, the) in PEGASUS searches but need not in MELVYL searches.
• Title Words (books)
  • MEL> f tw title words
    Example: f tw vitamin c cold
  • PEG> k title words
    Example: k vitamin c cold
• Subject Words
  • MEL> f su subject words
    Example: f su organic chemistry
  • PEG> k subject words
    Example: k organic chemistry
• Exact LC Subject Heading
  • MEL> f xsu subject heading subheading
    Example: f xsu chemistry organic handbooks
  • PEG> s subject heading--subheading
    Example: s chemistry organic--handbooks
  • Note that in PEGASUS, you must include any hyphenation in the heading; in MELVYL, you do not.

Subject Searching for Books

• Both systems have subject headings assigned from the Library of Congress Subject Headings lists.
• You could look up proper headings in LCSH books, but instead…
  1. Do a title word search (MELVYL) or keyword search (PEGASUS)
  2. Select one or more relevant records from those you retrieve.
  3. Look at the subject heading(s) assigned to those books.
  4. If you find new terminology that might prove useful, repeat the search as a subject or keyword search.

Other System Differences

• Truncation
  • MELVYL uses “#”
    Example: f tw electrochem#
  • PEGASUS uses “?”, but only in keyword searches.
    Example: k electrochem?
• Combining Searches
  • MELVYL allows combinations within a command line.
    Example: f au cotton and tw group theory
  • MELVYL also allows add-on commands
    Example: 1st command f au cotton, 2nd command and tw group theory. These are very useful for limiting a search (as by date or language) or narrowing a search with additional subject terms.
  • PEGASUS only allows single line combinations of keyword searches.
    Example: k cotton and group theory
• Call Number Searching
  • PEGASUS allows searching by call number; MELVYL does not.
  • Example: c qd401b761986
  • Useful for browsing what is available in a given area without running out to the stacks.

Searching for Journal Call Numbers

• Full Title (Journals)
  • MEL> f xpe journal title
    Example: f xpe journal of the american chemical society
  • PEG> t journal title
    Example: t journal of the american chemical society
  • Note that both automatically truncate at the end of exact title phrases. PEGASUS searches books and journals together; watch out for the one-word journal titles like Nature, Science
• Title Words
  • MEL> f pe journal title words
    Example: f pe eur# journal solid state chem#
  • PEG> k journal title words
    Example: k eur? journal solid state chem?
  • Note that both systems require at least three letters to truncate on. Since PEGASUS lumps journals and books together, and lists keyword results in reverse chronological order, MELVYL is usually easier for this type of search.
• When to Use PEGASUS vs. MELVYL for Journal Call Numbers
  • PEGASUS gives the most detailed holdings information, including current (unbound) issues.
  • MELVYL keeps journals in a separate file from books, and so can be easier when you have a single word title (e.g. Nature or Science) or when you have to use truncation.

Conference Papers

• On PEGASUS, use keyword search on the main words in the name of the conference.
• On MELVYL, conference may be listed:
  • as periodical (f pe)
  • as series (f se)
  • as corporate author (f ca)
  • as title words (f tw)
  and it’s difficult to predict which in some cases.

Monographic Series

• Some series are individually catalogued because the volumes vary widely in subject, e.g. ACS Symposium Series
• If so, the periodical record will say “see call number for individual volumes”
• On PEGASUS, use: k series name vol.#
  Example: k acs symposium 400
• On MELVYL, use: f se series name vol.#
  Example: f se acs symposium 400

Technical Reports

• Some are listed on MELVYL and PEGASUS, but not many. You will sometimes find them in footnotes, bibliographies or Chemical Abstracts searches.
• On catalogs, check the long form of the record for report numbers.
• Bring report numbers to SEL desk; we'll check to see if we have them, and verify on NTIS CD or fiche if necessary.

Government Documents

• Many US documents listed on PEGASUS, but some of these are unverified records.
• Check the location: if it's Government Publications, and there's a call number, it’s on the open shelves in GP.
• If no call number, the best strategy is to print out all pages of the long form of the PEGASUS record and take it to the Government Documents service desk for retrieval. Sometimes the information must be verified at the Main Reference Desk.

Dissertations

• UCSB Library owns few non-UCSB dissertations.
• Most UCSB dissertations are grouped together within broad subject areas e.g. QD 47.5 C2 S25 for chemistry dissertations. To find the dissertations from a given department search:
  • PEGASUS: k dissertations [department name]
  • MELVYL: f su dissertations [department name] ucsb
• Look up individual dissertations by author or title word like any other book.

Remote Access

• Both PEGASUS and MELVYL are available remotely, either by modem connection to the campus network.
• MELVYL is available by TELNET: telnet://melvyl.ucop.edu.
• PEGASUS is available by TN3270: tn3270://ccnh.ucsb.edu, a system similar to TELNET used to connect remotely to IBM mainframes.
• For both of the above, you must have the appropriate software (telnet or tn3270) loaded on your computer. Both are available on the Web as freeware. See the InfoSurf pages on MELVYL and PEGASUS respectively for links to sources of this software.
• MELVYL is available with a WorldWide Web interface.
• No password is required for the book catalogs, but MELVYL requires one for the article databases and the UPDATE command.

For more information on PEGASUS and MELVYL, see the InfoSurf Catalogs page.

This page created by Chuck Huber (huber@library.ucsb.edu).

Grace Baysinger, Head Librarian and Bibliographer
Swain Chemistry and Chemical Engineering Library, Stanford University Libraries
graceb@stanford.edu