<ref name="Wilson_&_Billen_2008">{{cite journal |first1=E. O. |last1=Wilson |first2=J. P. J. |last2=Billen |year=2008 |title=Social insect histology from the nineteenth century: the magnificent pioneer sections of Charles Janet |url=https://antcat.org/documents/4251/Billen&Wilson_2008_Arthropod_Struct_Devel.pdf |journal=Arthropod Structure and Development |publisher= |volume=37 |issue= |pages=163–167 |doi= }}</ref>