Rolf Kalmuczak was a prolific German author born in 1938 in Nordhausen and passing away in 2007 in Garmisch-Partenkirchen. Throughout his career, he worked as a newspaper editor, contributed to Stern magazine, and co-authored the popular Jerry Cotton series. Under more than 100 pseudonyms, he published numerous works, including youth books, film scripts, crime novels, and booklet-novels. Kalmuczak is best known for creating the TKKG book series under the name Stefan Wolf. He lived in Garmisch-Partenkirchen with his wife and daughter.