https://archive.org/details/top-welt-schockierende-entdeckungen-die-uns-dazu-veranlassen-die-geschichte-zu-uberdenken
https://archive.org/details/die-verborgene-felsmalereien-von-suedamerika-arte
https://archive.org/details/jenseits-von-pluto-arte
https://archive.org/details/max-bentow-das-hexenmaedchen