Say, does anyone know what the #2 bestseller in German non fiction is?

“Mein Kampf” is a bestseller again in Germany, with demand so outstripping supply that it is virtually impossible to get one’s hands on a copy.
Adolf Hitler’s anti-Semitic screed, which was republished in Germany earlier this year in a scientifically annotated edition, is currently the country’s second-best selling nonfiction book, according to one bestseller list, surpassed in sales only by a book about “The secret lives of Trees.” But this reporter was unable to purchase a copy, learning from salespeople in about a dozen bookstores in three cities that “Mein Kampf” can only be pre-ordered, is unavailable for immediate purchase and will remain so for the foreseeable future.
“You can order it, but I don’t know when it’ll arrive,” a shop assistant in a bookstore at Berlin’s famous KaDeWe department store told The Times of Israel during a recent visit.