@article{{EES}{}, author = {Son, N., Hoa, N., Dung, L.}, title = { Composition of bird species in Huu Lien Nature Reserve, Lang Son province}, journal = {VNU Journal of Science: Earth and Environmental Sciences}, volume = {27}, number = {1}, year = {2011}, url = {https://js.vnu.edu.vn/EES/article/view/1496} }