Gaya APA

Hiraku, T. (1991). What Are Numbers? (6 to 99) : A Child's First Mathematics Program (6) (cet.1). : Time life books.

Gaya MLA

Hiraku, Toyama. "What Are Numbers? (6 to 99) : A Child's First Mathematics Program (6)". cet.1 : Time life books, 1991. Text.