by Yang Xiaoli, China Meteorological Administration, Lanzhou (China), Institute of Arid Meteorology, Pu Jinyong, The Agrometeorological Experiment Station of Tianshui, Tianshui (China), Ma Pengli, Lanzhou Regional Climate Center, Lanzhou (China)
Published in Xi bei nong lin ke ji da xue xue bao.Zi ran ke xue ban (01.09.2009)