# Building a Library

Is math.stackexchange a good place to ask where to find copies of books? Say I want to get my hands on a copy of Baby Rudin, would it be appropriate to ask on this website where one can found? I use this example because I know that there are free online copies of questionable legality, and if one does a quick check on Amazon a copy of this book will cost you at least \$40. However, I got bought the third edition for about \$9 by buying an Indian edition, which I was extremely happy to find as I am not a very big fan of pdf copies of books. Similarly, when I was buying a copy of Dummit and Foote, I saw that most copies were in the many hundreds of dollars, with there being new paperback copies being sold on Amazon for \$999 and used copies for as much as \$129. I do not recall exactly where I found mine, but I remember buying it online for under \$20. Again, it was a copy using cheaper paper (I believe an Indian edition) but the material is all there and it has held together excellently. If I am trying to find a cheaper version of a math textbook, is this an appropriate place to ask where people have found theirs? If not, where can I do so? • I lean towards thinking math.se is not the right place for that question. Sites like abebooks.com are good resources for finding such books, but I don't know anywhere the aggregates such resources – postmortes May 4 at 8:15 • That exactly is my concern, abebooks is just another online store that often has cheap books, but it is not a place I can ask someone else where they got their books from. I don't know of any place where this is appropriate for finding math texts, and it seems like it wouldn't be terribly off-topic here as this sort of question is certainly related to learning math (especially for students who cannot afford to drops hundreds or thousands of dollars on a few texts) and often has a definite answer: i.e. "X store sells Y book for Z dollars, which is cheaper than Amazon's pricing". – PhysMath May 4 at 8:32 • These sorts of requests are best suited for chatrooms. What about questions for the best software to learn math, or the best calculator to enhance learning, and where to get both cheaply. Asking for good references is on topic, but asking for where one can buy those references, calculators, software, etc., is not. Imagine answers of the sort: "I have an extra copy of Baby Rudin that I'll sell you for$15." Math.se, nor any SE website, is designed to be a marketplace, or to promote marketplaces. – amWhy May 4 at 13:47

Is math.stackexchange a good place to ask where to find copies of books?

There are two different kinds of requests:

• You have a specific topic X in mind and want to know related books;
• You have a specific (mathematics) book Y in mind, and want to purchase a cheaper legal copy.

For the first kind, you can ask questions on the main site with tags book-recommendation and or reference-request (together with other appropriate tags). For example, see this question: Big list: Free textbooks and resources. See also Book recommendations [closed] on physics.SE.

The second kind seems to be tangential to maths.SE, if not off-topic. An answer such as "there is a bookstore Z on 50th street" may be too localized to be useful. Nevertheless, there were examples on the main site of this kind before: see Inexpensive Math Books.

If I am trying to find a cheaper version of a math textbook, is this an appropriate place to ask where people have found theirs?

You can try money.SE. In particular, see this example: What are some sites that offer decent deals on college textbooks? .

• Examples of a similar post existing on math.se are not evidence they are welcome on math.se. Fallacy. Existence implies "all such questions are welcome." – amWhy May 4 at 14:19