Among the more notable are: (a) a classic text is Instructional Technology Foundations edited by Robert Gagné; (b) a more recent classic is Principles of Instructional Design by Bob Gagné, Walt Wager, Katharine Golas, and John Keller; (c) The Conditions of Learning (4th ed.) by Gagné should be considered a foundation piece; and (d) the International Encyclopaedia of Educational Technology edited by Tjeerd Plomp and Don Ely is another good source. One could also visit the Websites of the Association for Educational Communications and Technology (www.aect.org) and the International Board of Standards for Training, Performance and Instruction (www.ibspti.org) and find pointers to other relevant sources and considerations.