Comparative study of fusion rate induced by different dosages of Escherichia coli–derived recombinant human bone morphogenetic protein-2 using hydroxyapatite carrier - Lee, Jae Hyup; Yu, Chang Hun; Yang, Jae Jun; Baek, Hae-Ri; Lee, Kyung-Mee; Koo, Tae-Young; Chang, Bong-Soon; Lee, Choon-Ki (Spine Journal, 2012)