Reference materials
The relevant service manual for that aircraft.
Mimi A. Stankowich has written: 'Learning to use reference material'
special reference material
When you asked your question, you asked a reference question. You are asking me for information. That is a reference question requesting information from me. I am your reference material to answer this particular question. For other types of research, you need different types of reference material. If you are doing research on how to find or make something, a good reference can show you how others have done the same thing and problems they have run across in the past. Using such material is called avoiding "Reinventing the wheel." If you are doing original research, you need to know what others have done in a similar vein. That way you can show why what you are doing is original.
From a book
See the link below for U.S. rules.
You need to include some kind of reference on any memorandum so that the memo can be later quickly identified as relating to other material.
References can be noted at the end of the page or in the index bibliography if the reference material is published as a book or some journal /magazine - other wise you cannot give self reference to your own article.
Same material as any other uniform
Geologists reference a material's density in reference to it's weight. Density is the material's weight divided by the weight of an equal volume of water.
AFMAN 24-204(i)