[2] Chen C, Liao G P, Shi X H, et al. Journal of Hunan Agricultural University, 2011, 37(5): 474.
[5] Yang W, Sigrimis N, Li M, et al. Correlations between Nitrogen Content and Multispectral Image of Greenhouse Cucumber Grown in Different Nitrogen Level. Computer and Computing Technologies in Agriculture VI, 2012. 456.