Eg:
Iverson, K.E., APL in Exposition, IBM Corporation, 1972-01.
Iverson, K.E., Introducing APL to Teachers, IBM Corporation, 1972-07.
Iverson, K.E., Algebra: An Algorithmic Treatment, Addison-Wesley, 1972.
Iverson, K.E., Algebra as a Language, Appendix A of Algebra: An Algorithmic Treatment, Addison-Wesley, 1972.
Iverson, K.E., An Introduction to APL for Scientists and Engineers, IBM Corporation, 1973-03.