Srivastava, U. S., & Srivastava, P. D. 1961: On the Hydrogen-Ion Concentration in the Alimentary Canal of the Coleoptera. - Beiträge Zur Entomologie = Contributions to Entomology 11(1-2): 15–20 - doi: 10.21248/contrib.entomol.11.1-2.15-20