Yao Zhang Lihua Zheng Hong Sun Wei Yang 0022 An Optical Detector for Determining Chlorophyll and Nitrogen Concentration Based on Photoreaction in Apple Tree Leaves. 409-421 2015 21 Intell. Autom. Soft Comput. 3 https://doi.org/10.1080/10798587.2015.1015768 db/journals/iasc/iasc21.html#ZhangZSY15