Havighurst, R. J. (1972). Development tasks and education (3rd ed.). David McKay Company, Inc..
Chicago-referens (17:e uppl.)Havighurst, Robert James. Development Tasks and Education. 3rd ed. New york: David McKay Company, Inc., 1972.
MLA-referens (8:e uppl.)Havighurst, Robert James. Development Tasks and Education. 3rd ed. David McKay Company, Inc., 1972.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.