APA (7th ed.) Citation

Montessori, M., & Carter, B. B. The secret of childhood.

Chicago Style (17th ed.) Citation

Montessori, Maria, and Barbara Barclay Carter. The Secret of Childhood.

MLA (9th ed.) Citation

Montessori, Maria, and Barbara Barclay Carter. The Secret of Childhood.

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