@article{Jing Li_620, author = {Jing Li, Hongbing Liu, Caiyun Li, Long Li}, title = {Changes of Green-up Day of Vegetation Growing Season Based on GIMMS 3g NDVI in Northern China in Recent 30 Years}, publisher = {SCIENTIA GEOGRAPHICA SINICA}, year = {2017}, journal = {SCIENTIA GEOGRAPHICA SINICA}, volume = {37}, number = {4}, eid = {620}, pages = {620-629}, keywords = {green-up day of growing season;GIMMS 3g NDVI;harmonic analysis;polynomial fitting;correlation}, doi = http://geoscien.neigae.ac.cn/EN/10.13249/j.cnki.sgs.2017.04.016 }