https://archive.org/details/top-welt-wer-lebt-am-boden-des-marianengrabens
https://archive.org/details/discovery-secret-underground-verborgene-geheimnisse-kaliforniens-versteckter-weltuntergang-gungywamp
https://archive.org/details/metamorphosis-illustra-media
https://archive.org/details/max-bentow-rotkaeppchens-traum