1. REFERANS1 Graff K. (2005). Untersuchungen von Zusammenhängen zwischen morphologischen Merkmalen des Euters, der Eutergesundheit und melktechnischen Parametern bei Tieren der Rasse Deutsches Holstein. Dissertation Martin-Luther-Universität, Halle Wittenberg, Germany.
2. REFERANS2 ISO. 2007a. International Organization for Standardization. ISO 5707. Milking machine installations, construction and performance. Geneva. ISO.
3. REFERANS3 ISO. 2007b. International Organization for Standardization. ISO 6690. Milking machine installations - mechanical tests. International Organization for Standardization. Geneva. ISO.
4. REFERANS4 Mein G A (1992). Action of the cluster during milking . In A. J. Bramley, & F. H. Dodd, Machine Milking and Lactation (S. 435 pp. ). Burlington, VT 05401, USA: Insight Books.
5. REFERANS5 Nyhan J F (1968). Effect of vacuum fluctuation on udder disease. In: Proceedings of the Symposium on Machine Milking, Shinfield; p. 71–82.