Cita APA (7a ed.)

Cappella, A. (1985). The natural way: The Billings method. BBE.

Cita Chicago Style (17a ed.)

Cappella, Anna. The Natural Way: The Billings Method. Torino, Italy: BBE, 1985.

Cita MLA (8a ed.)

Cappella, Anna. The Natural Way: The Billings Method. BBE, 1985.