Pennsylvania State Beekeepers' Association & Pennsylvania State Beekeepers' Association. (1928). Report of the Pennsylvania State Beekeepers' Association. Published by direction of the Secretary of Agriculture Harrisburg Publishing Co., state printer.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিPennsylvania State Beekeepers' Association এবং Pennsylvania State Beekeepers' Association. Report of the Pennsylvania State Beekeepers' Association. Harrisburg, PA: Published by direction of the Secretary of Agriculture Harrisburg Publishing Co., state printer, 1928.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিPennsylvania State Beekeepers' Association এবং Pennsylvania State Beekeepers' Association. Report of the Pennsylvania State Beekeepers' Association. Published by direction of the Secretary of Agriculture Harrisburg Publishing Co., state printer, 1928.