The bee genus Chilicola in the tropical Andes : with observations on nesting biology and a phylogenetic analysis of the subgenera (Hymenoptera: Colletidae, Xeromelissinae) Q Science
A beginner’s star-book; an easy guide to the stars and to the astronomical uses of the opera-glass, the field-glass and the telescope Q Science
Beitrag zur Kenntniss der Spongienfauna des malayischen Archipels und der chinesischen Meere Q Science
