APA

heinst m., . (1992). my first number book. london: dorling kindersley.

Chicago

heinst marie, . 1992. my first number book. london: dorling kindersley.

Harvard

heinst m., . (1992). my first number book. london: dorling kindersley.

MLA

heinst marie, . my first number book. london: dorling kindersley. 1992.