Gaya APA

Ritchie, I. (1977). A Guide to the Implementationn of the ISO 14000 Series? (1). : Prentice Hall, Upper Sadlle River.

Gaya MLA

Ritchie, Ingrid. "A Guide to the Implementationn of the ISO 14000 Series?". 1 : Prentice Hall, Upper Sadlle River, 1977. Text.