Kopp, J., & Sperber, J. (1981). Chronik der Familie Sperber: Bearb. von Jenny Kopp, geb. Sperber. v. Sperber.
Citazione stile Chigago Style (17a edizione)Kopp, Jenny, e Jenny Sperber. Chronik Der Familie Sperber: Bearb. Von Jenny Kopp, Geb. Sperber. [Schleswig]: v. Sperber, 1981.
Citatione MLA (8a ed.)Kopp, Jenny, e Jenny Sperber. Chronik Der Familie Sperber: Bearb. Von Jenny Kopp, Geb. Sperber. v. Sperber, 1981.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.