1. Dąbrowska, B., Pokojska, H., Suchorska-Tropiło, K. 2000.InUniversity of Life Sciences ed., Methods of laboratory seed evaluation. SGGW, Warsaw. 1-111**.
2. Heydecker, W. 1972. Vigour.InE.H. Roberts ed.,Viability of Seeds. Chapman and Hall, London: 209-252.
3. ISTA. 2011. Chapter 5.InThe International Seed Testing Association ed., International Rules for Seed Testing. Bassersdorf, Swizerland. 5-53.
4. SAS Institute Inc. 2004. SAS. 9.1. Companion for Windows. SAS Publishing, Cary, NC, USA. Struik, P.C., Wiersema,S.G. 1999. Seed Potato Technology. Wageningen Accademic. Pub. Wageningen, The Netherlands. 1-383.