Wikipedia:Citing textbooks

This is an essay. It contains the advice or opinions of one or more Wikipedia contributors. This page is not an encyclopedia article, nor is it one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community. Some essays represent widespread norms; others only represent minority viewpoints.

Textbooks are defined as

There are several situations in which textbooks should be completely avoided as your primary source of information about a subject. Such textbooks may not be the worst possible sources, but far better sources are always available for verifiable information, and they may lead you into error. These situations include:

• Primary school textbooks for mathematics, science, and language are usually oversimplified to help young learners understand the concepts more easily. For example, you may have thought that there are only two forms of biyu, that a full stop (.) is a point, that there are only seven verb tenses (present simple, present continuous, present perfect, past simple, past continuous, past perfect, and future simple). These are obviously untrue.
• Old textbooks, which may be so terribly outdated that they are almost completely invalid. For example, many textbooks still use Herodotus' version of the Great Pyramid. (Even some textbooks published now still include them! Gordon Bennett!) Slaves built the pyramids, didn't they?

In other instances, the textbook may be entirely accurate—or it may not.

• Introductory-type textbooks often simplify like primary school textbooks do. You don't want people going everywhere saying that there are only three notable battles on the Persian Wars. There are exceptions to this one though. If a topic is REALLY obscure, or if the textbooks provides 'did you know' sections that are REALLY RIP-ROARING, you can cite textbooks.
• Sometimes textbooks can also act as a good tertiary source. Textbooks on topics like social sciences could be the result of lots and lots of months spent in the library. These textbooks are good because they cite all the sources where their statistics etc. come from. You can put them in your article (citing both). Yay! (If you are really lazy, and the textbook authors aren't, you could copy the way they cite the source... but then again, the info is very limited.)
• When the article in question is about the textbook, the book
  becomes a primary source for information about itself
  and must be used with caution.