[en] [Gutenberg 34006] • Rustic Sounds, and Other Studies in Literature and Natural History Createspace Independent Publishing Platform
[es] [Gutenberg 50430] • Historia natural y moral de las Indias (vol 2 of 2) Fondo De Cultura Economica USA
[en] [Gutenberg 61273] • An Introduction to Nature-study Palala Press
[en] [Gutenberg 53300] • Nature's Teachings: Human Invention Anticipated by Nature Cambridge University Press
[en] [Gutenberg 2530] • The Malay Archipelago, Volume 1 / The Land of the Orang-utan and the Bird of Paradise; A Narrative of Travel, with Studies of Man and Nature Createspace Independent Publishing Platform