https://archive.org/details/10-grunde-warum-der-megalodon-noch-am-leben-sein-konnte
https://archive.org/details/discovery-secret-underground-verborgene-geheimnisse-bermuda-dreieck-der-grossen-seen
https://archive.org/details/kaffee-koffein-gesund-oder-eher-schaedlich-dr.-weigl