it appears to me that you have some problem with references. It is caused by the fact, that you still have something written after the name of the reference. It should be just in the first reference but then you should use just the name, e.g. <nowiki><ref name="ring"/></nowiki>. If you delete everything what is after the reference's name in the second and further references, then it should function. If not, let me please know. --[[User:Zuzka|Zuzka]] ([[User talk:Zuzka|talk]]) 20:36, 5 November 2016 (CET)
Dear dr. Rybaříková
Thank you for your suggestion. I already repaired it.
--[[User:Cernab|Cernab]] ([[User talk:Cernab|talk]]) 14:10, 6 November 2016 (CET)