APA (7th ed.) Citation

Flower, Berman, & Powell. (1989). Built your vocabilary 1. Language Teaching Publication.

Chicago Style (17th ed.) Citation

Flower, Berman, and Powell. Built Your Vocabilary 1. Hove,England: Language Teaching Publication, 1989.

MLA (9th ed.) Citation

Flower, et al. Built Your Vocabilary 1. Language Teaching Publication, 1989.

Warning: These citations may not always be 100% accurate.