Fenson, L. (1990). Human development 90/91 (18ª ed.). The Dushkin.
Cita Chicago (17th ed.)Fenson, Larry. Human Development 90/91. 18ª ed. The Dushkin, 1990.
Cita MLA (9th ed.)Fenson, Larry. Human Development 90/91. 18ª ed. The Dushkin, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.