LI Guang-liang, JING Yan-qiu, LIU Jian-jun, ZHU Jin-feng, XIE Xiao-hui, JIN Lei, ZHANG Hong-li, YANG Hong. 2011: Effect of different planting densities on free amino acids content in burley leaves. Journal of Southern Agriculture, 42(6): 599-602. DOI: 10.3969/j.issn.2095-1191.2011.06.007