@book{3531,
	author = {Mulder, Mauk.},
	title = {Group structure, motivation, and group performance /},
	publisher = {Mouton},
	year = {[1963]},
	address = {The Hague,},
	note = {"Revised edition of 'Groepsstructuur, motivatie en prestatie' ... 1958. It contains two parts, published ... in Acta psychologica, 1959."}
}