CJCP     2019 21 (6):  558-561    ISSN: 1008-8830  CN: 43-1301/R Clinical effect and safety of different maintenance doses of caffeine citrate in treatment of apnea in very low birth weight preterm infants: a prospective randomized controlled trial ZHANG Xiao, ZHANG Hai-Tao, LYU Yong, WANG Li-Feng, YANG Zhen-Ying Department of Neonatology, Tai'an Maternity and Child Care Hospital, Tai'an, Shandong 271000, China Received: 2018-11-15  Revised: 2019-04-29  Online: null Supporting info