Swarm control Demuth, Geo. S. (George S.) creator text book Washington U. S. Govt. Print. Off 1921 1921
print
ENG Caption title. Bees Swarming Farmers' bulletin (United States. Dept. of Agriculture), no. 1198 https://www.biodiversitylibrary.org/bibliography/54216 63227342 10.5962/bhl.title.54216 NIC