Long, K.D., Hue, L.X., Hoa, D.T. and Phong, P.H. 2013. A preliminary study on bees (Hemenoptera: Apoidea: Apiformes) from Northern and North central Vietnam. Academia Journal of Biology. 34, 4 (Jan. 2013), 414–421. DOI:https://doi.org/10.15625/0866-7160/v34n4.2676.