A、Current issues are kept on the shelves. B、Back issues are bound together in volumes. C、The procedure of borrowing a back issue

Li Hud: Pardon me. I’ m trying to find articles on ecology. Can you help me?
Lib: You’d begin by looking into some of the specialised indexes such as The Applied Science and Technology In dex, or the Bibliography and Index of Ecology.
Li Hud: What will I find in these indexes?
Lib: In the Applied Science and Technology Index, for example, you will find articles published in 297 periodicals. So you could look under" ecology" and then under such subheadlines as "methods of research" or "research techniques", etc. You will find everything that was published in any of those 297 magazines and journals in the period of time covered by the index volume you’ re looking into. This one, for example, goes from November 10th, 1990 to December 28th,2000.
Li Hud: Suppose I find several listings of articles that may be helpful to me. What do I do then?
Lib: You should go to the appropriate volume or abstracts to learn more about the articles and decide which one or ones are relevant to you. Or you can just find the articles and skim them.
Li Hud: Where could I find those articles?
Lib: If the articles has appeared in the last year or so, check in the Periodical Reading Room. Current issues of a great many magzines are kept on the racks and shelves there, arranged alphabetically by title.
Li Hud: Can I borrow those periodicals.*
Lib: No. But you can always Xerox a particular article if you really want it to take home.
Li Hud: Yes. But is that expensive? By the way, how much does Xeroxing cost here in the library?
Lib: It’s usually a dime a page in the library.
Li Hud: Well, what if the article was published more than a year ago?
Lib: Back issues of periodicals are bound together in volumes and shelved with the books in the stacks. You look up the call number of the periodicals just as you do for books. On a call slip you record the call numbers, the date of the article you need and the bound volume number in which it appears. Then you follow the same procedure as you would for a book. Still you may as well find materials on microfilm or microfiche.
Li Hud: What are "microfilm" or "microfiche" ?
Lib: Since we couldn’t keep all the back issues in the li brary, we put them on miniature film. That’s "micro film". And "microfiche" is a tiny square film no bigger than your thumbnails.
Li Hud: How could I use it?
Lib: When you find out the call slip, bring it to me. Then I’ll show you how to use the machine to blow it up to the original size.
Li Hud: You’ ve been very helpful and patient. I really appreciate it. Before I go, could you tell me what other materials you keep here in the Reference Room?
Lib: Sure. Besides indexes for books, periodicals and news papers, you’ll also find comprehensive and concise en cyclopedias, dictionaries. Lexicons, atlases, biographies, bibliographies, annotated bibliographies and almanacs.
Li Hud: I’ll have to use one of your dictionaries to find out what all those words mean!
Lib: Why don’t you just brosse through the reference books for a while and see what’s in them. Don’t worry. You’ll get used to it soon.
Li Hud. Hope I’ll do that soon. Thank you indeed for your help.
Lib: My pleasure. And don’t be shy if you have any more questions. That’s what I’ m here for.