Helga Feider

A comparative syntactic description of spoken and written English

Helga Feider, 1969 .

Psychogenesis and the History of Science

Jean Piaget, Helga Feider, J. Piaget, 1988 .

THE ACQUISITION OF PERSON PRONOUNS IN FRENCH-SPEAKING CHILDREN*

Helga Feider, M. Legerstee, Maria Legerstee, 1986 .