APA
Williams H. M., . (1961). Education of the severely retarded child: Classroom programs. USA: U S Department of Health Education & Welfare.
Chicago
Williams Harold M, . 1961. Education of the severely retarded child: Classroom programs. USA: U S Department of Health Education & Welfare.
Harvard
Williams H. M., . (1961). Education of the severely retarded child: Classroom programs. USA: U S Department of Health Education & Welfare.
MLA
Williams Harold M, . Education of the severely retarded child: Classroom programs. USA: U S Department of Health Education & Welfare. 1961.