Sawatthum, A. “Role of Stingless Bee, Tetragonula Pegdeni and European Honey Bee, Apis Mellifera in the Pollination of Confectionery Sunflower”. Thai Journal of Science and Technology, vol. 9, no. 3, May 2020, pp. 368-77, doi:10.14456/tjst.2020.26.