Mollie and Russel’s bestselling college textbook, Children: Development and Relationships (1967, 1973, 1977, 1982), was based on the theories of Erik Erikson and Jean Piaget, and the 1982 edition was also framed by Bronfenbrenner’s (1979) theory of human ecology. As did all of their writing on child development, Children emphasised the interaction of cognitive development, physical development, social relationships, and cultural context. Written in concise and clear language understandable to undergraduate students, the book sold well in Canada, New Zealand, and India, as well as in the U.S.