Sacbrood, a disease of bees White, G. F. (Gershom Franklin), 1875- creator text book Washington Govt. print. off 1913 1913
print
ENG Bees Diseases Circular (United States. Bureau of Entomology), no. 169 https://www.biodiversitylibrary.org/bibliography/56965 27980294 10.5962/bhl.title.56965 NIC