ULTRASTRUCTURE AND DEVELOPMENT OF POLLEN GRAIN IN POPULUS DELTOIDES BARTR. VAR. DELTOIDES CV. HARVARD (I-63/51)
Fan Ruwen Huang Jinsheng & Li Yongjing(Department of Forestry)
JOURNAL OF NANJING FORESTRY UNIVERSITY . 1983, (03): 13 -18 .  DOI: 10.3969/j.jssn.1000-2006.1983.03.003