Cita APA (7a ed.)

Ziefert, H., & Plecas, J. (2000). Grandpas are for finding worms. Puffin Books.

Cita Chicago Style (17a ed.)

Ziefert, Harriet, y Jennifer Plecas. Grandpas Are for Finding Worms. New York, NY: Puffin Books, 2000.

Cita MLA (8a ed.)

Ziefert, Harriet, y Jennifer Plecas. Grandpas Are for Finding Worms. Puffin Books, 2000.