9Darwish, Atef M, Mohamad, et al. Prevalence and predictors of deficient dietary calcium intake during the third trimester of pregnancy : The experience of a developing country [ J ]. Journal of Obstetrics & Gynaecology Research, 2012, 35 (1) :106 -112.
10Costa ML, Krupa FG, Rehder PM, et al. Forearm bone min- eral density changes during postpartum and the effects of breastfeeding,amenorrhea, body mass index and contracep- tive use [ J ]. Osteoporosis Int,2012,23 (6) : 1691 - 1699.
