Gaya APA

Wardiyah,{et.all}, . et al (1986). Mental Retardation : a life cycle approach . United States of America: Merrill Publishing Company A Bell & Howell Information Company.

Gaya MLA

Wardiyah,{et.all}, . et al. "Mental Retardation : a life cycle approach". United States of America: Merrill Publishing Company A Bell & Howell Information Company, 1986. Text.