@book{89683,
	author = {Ferster, Charles B. and Skinner, Burrhus Frederic},
	title = {Schedules of reinforcement},
	publisher = {Appleton-Century-Crofts},
	year = {[1957]},
	series = {The Century Psychology Series},
	address = {New York},
	note = {"Most of the work ... was carried out under contract to the Office of Naval Research under Contracts No. N5ori-07631 and M5ori-07656 with Harvard University ... between September 1, 1949 and June 30, 1955."}
}