Kaufman, Peter B· Thomas J Carlson· Kaufman B Kaufman· Harry L Brielmann· Sara Warber· Leland J Cseke· James A Duke (1999). Natural Products from Plants. Boca Raton: CRC Press. σελίδες 261. 084933134X.
Gräslök, from Den virtuella floran, retrieved on June 13, 2006, The facts mentioned on the site apply to Sweden, which is in the northern part of the habitat zone.
George J. Hochmuth· Robert C. Hochmuth· Steve Kostewicz & William Stall (1987). «Row Covers for Commercial Vegetable Culture in Florida». Institute of Food and Agricultural Sciences (University of Florida). Ανακτήθηκε στις 19 Μαρτίου 2015.
vsegost.com
ГОСТ Р 52096-2003. Творог. Технические условия. (Russian state standard GOST R 52096-2003. Tvorog. Specifications; in Russian). The standard for tvorog is defined separately from the standards for cheeses.