Xia Yao Yan Zhu YongChao Tian Wei Feng Weixing Cao Exploring hyperspectral bands and estimation indices for leaf nitrogen accumulation in wheat. 89-100 2010 12 Int. J. Applied Earth Observation and Geoinformation 2 http://dx.doi.org/10.1016/j.jag.2009.11.008 db/journals/aeog/aeog12.html#YaoZTFC10