Literature 7: Sang Li-Qin,Xu Sheng-Quan. Melissopalynological identification of nectar woody plants from the honey of Apis cerana ceraca in Qinling Mountains. Journal of Environmental Entomology, 2021,43(2):379-386. Literature in Chinese, download from: 基于蜂蜜孢粉学鉴定秦岭中华蜜蜂的蜜源木本植物 - 中国知网