The direct decendants of Johannes von Rönge currently reside in South Africa, and can be easily contacted for a copy of the family tree, and a copy of the patents of nobility, which I cant cite on the article, since the family have the copyright. Copies are available for a fee. I suggest that it is not I, but users with less topical knowlege that are mistaken. The copy of the autobiography above is an english translation of the fourth german edition of the original, which was first printed in english during his exile, not in german. I dont see how citing the golden book of polish nobility (a loose translation of the title) is unsourced, since it cites a known and respected work.  It is a well known fact that german names into antiquity often have variant spellings, I have come across the family's name spelled as VON RVNGE (the variant used in the patents of nobility), VON ROENGE, VON RöNGE, VON RONGE, and even one case of VAN RONGE (apparently a political move to make the bearer sound Dutch instead of German post WW2) as well as some variants sans von. In the end what variant is used on wikipedia matters little, since it is not a reliable source anyway.