CJCP     2001 3 (3):  299-300    ISSN: 1008-8830  CN: 43-1301/R Levels of cerebrospinal fluid β-endorphin in premature infants with primary apnea LI Hei-Da, DENG Guo-Quan, HUANG Xin-Hua, HU Chun-Yu Received: null  Revised: null  Online: null Supporting info