Conda-Sheridan M, Park EJ, Beck DE, Reddy PV, Nguyen TX, Hu B, Chen L, White JJ, van Breemen RB, Pezzuto JM, Cushman M. Design, synthesis, and biological evaluation of indenoisoquinoline rexinoids with chemopreventive potential. J Med Chem. 2013 Mar 28; 56(6):2581-605.