1. BARTHEL
1924 Le Lait p. 725.
2. BOEEKHUT
1917 Vereeniging tot Exploitatie eener Proefzuivelboerdereij te Hoorn.
3. 1920, 1921 Agricultural Experiment Station, Iowa State College of Agriculture and Mechanic Arts;HAMMER;Bulletins,1919
4. ORLA-JENSEN 1919 The Lactic Acid Bacteria. Royal Danish Society of Sciences. Section for Natural Sciences and Mathematics 8th Series 2 132.
5. STORCH
1919 Forsgs 0laboratoriets 102 Beretning.