Synthesis of 1-Substituted Carbazolyl-1,2,3,4-tetrahydro- and Carbazolyl-3,4-dihydro-β-carboline Analogs as Potential Antitumor Agents oleh Ji-Wang Chern, Sheau Farn Yeh, Lan-Chun Tu, Chia-Ching Liaw, Yao Haur Kuo, Chun-Ling Lin, Yao-To Chang, Ya-Ching Shen