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University of Southern Maine
Libraries & Learning

*Natural and Applied Sciences: Home

A library research guide for Lewiston-Auburn College's NAS (Natural and Applied Sciences) liberal arts major.

Update on MEDLINE access

There are now 2 ways to search MEDLINE.  You can use PubMed or our new MEDLINE (Ovid). Tutorials for these are linked below, under Searching Tips.  (8/15/18)

If you have any questions, please do not hesitate to reach out to a librarian using Ask/Chat with a Librarian

Key Resources for NAS

This introductory guide for undergraduate students in the NAS program provides useful tips on:

  • how to locate books/ebooks and journals
  • recommended databases
  • finding sources of biology videos
  • cite and manage your sources, and how to do a lit review

Anatomy Websites can be helpful to practice your knowledge.

These resources contain basic overview information that can be useful when you're just beginning your research:

Related Guides:

Once you have a good understanding of your topic and have selected a few keywords, OneSearch is a great place to start your research.  It is a convenient way to search almost all of the library's resources using a single search box, and you can easily apply limits to more narrowly focus your search.

You can search for books at USM or in other libraries by using the links below. If you're not sure how to find what you're looking for, Ask Us!

Sign-in through the MyUSM portal for access to thousands of ebooks via the URSUS catalog or one of our ebook databases below.  In URSUS, you have access to books listing "USM Access", "UM System-wide Access" or Maine Infonet Access. 

Searching Tips & Tutorials

  • Most databases allow for searching with Boolean operators (AND, OR, NOT).
    • Use AND to focus your search and combine different aspects of your topic
    • Use OR to broaden your search and find sources that use different words for the same concept.
    • Use NOT to omit certain terms from your results.
  • Use an asterisk (*) to truncate words if you want to search for all words with that root. For example, “environment*” would search for environment, environmental, environmentalism, etc.
  • Put quotes around a phrase that you want the database to search as a phrase, rather than as individual words.
  • Group synonyms inside parentheses using OR between each one


URSUS is the combined library catalog for the entire University of Maine system. You can search the entire system, or select University of Southern Maine Libraries in the drop-down.

Other helpful tips:

  • If you find a book that is relevant to your needs, look at the "Subject" area of the book's record. Click on a few of the subjects to find other similar books.
  • In many of the book records, you can look at the table of contents - click the link under the "Inside This Book" heading. This can help you determine if a book is right for your research.
  • If USM doesn't have a book you want, click the "Request" button at the top of the page and we can get it for you through our very fast courier service.

Most databases, as well as URSUS and MaineCat, assign subjects to books and articles. A subject is a designated word or phrase that describes an idea or concept and groups all articles or books about that concept together.

  • Subjects are also variously called descriptors, controlled vocabulary, headings, or index terms.
  • To search by subject you have to know the exact subject term. Most databases that use subjects have a Thesaurus that you can use to look up subject terms. You can also do a keyword search, find a book or article that is relevant to your research, and look at the subject terms assigned to it.
  • URSUS and MaineCat use Library of Congress Subject Headings, and each database will have its own list of subject headings, so you will have to look up subjects in each database independently.

There are many ways you can get research materials from other libraries. In the vast majority of cases, there is no charge to you for this service!

  • From URSUS, use the  button at the top of an item's page.
  • From MaineCat, use the  button in the middle of an item's page.
  • From a database:
    • Select the item you want and find and click the  or "Article Linker" button (the placement on the page will vary by database).
    • If the library does not have access to the item, find and click the "Submit an Interlibrary Loan Request" link under Step 3 in the right panel.

Ask A Librarian

Your Librarian

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Maureen Perry
Library, Lewiston-Auburn College, Lewiston
(207) 753-6546