The following excerpt is from the Circular 21: Reproduction of Copyrighted Works by Educators and Librarians, section C, 2b, ii, pg. 6.
Single Copying for Teachers
A single copy may be made of any of the following by or for a teacher at his or her individual request for his or her scholarly research or use in teaching or preparation to teach a class:
Multiple Copies for Classroom Use
Multiple copies (not to exceed in any event more than one copy per pupil in a course) may be made by or for the teacher giving the course for classroom use or discussion; provided that:
*Students should refer to Fair Use guidelines.