Willard W. Hartup

Social cognition and social development : a sociocultural perspective

E. Tory Higgins, D. Ruble, E. Higgins, 1985 .

The Company They Keep: Friendship in Childhood and Adolescence.

W. Hartup, W. Bukowski, A. Newcomb, 1996 .

Friendships and their Developmental Significance

W. Hartup, Willard W. Hartup, 2022, Childhood Social Development.

Having Friends, Making Friends, and Keeping Friends: Relationships as Educational Contexts. ERIC Digest.

W. Hartup, Willard W. Hartup, 1992 .

The Young Child: Reviews of Research

W. Hartup, Willard W. Hartup, Nancy L. Smothergill, 1974 .

Friends as Coworkers: Research Review and Classroom Implications

W. Hartup, Willard W. Hartup, Robert J. Zajac, 1997, The Elementary School Journal.