APA (7th ed.) Citation

Krüger, M., & Bielińska, H. (1957). Petra. Iskry.

Chicago Style (17th ed.) Citation

Krüger, Maria, and Halina Bielińska. Petra. Warszawa: Iskry, 1957.

MLA (9th ed.) Citation

Krüger, Maria, and Halina Bielińska. Petra. Iskry, 1957.

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