That is a terrific question...the best source is a bibliographical list on the Erickson Foundation web site: http://erickson-foundation.org/bibliography.html

This has more than 1st generation authors, however. So, to help nail it down a bit I have these on the top of my head: Haley, Lankton, Zeig, Rossi, Havens, Ritterman, Burns, Gilligan, Rosen, Parsons, and O'Hanlan. There are some others too...I'm sorry to have slighted them in my haste.