Vougogiannopoulou, K. Ferandin, Y. Bettayeb, K. Myrianthopoulos, V. Lozach, O. Fan, Y. Johnson, C.H. Magiatis, P. Skaltsounis, A.-L. Mikros, E. Meijer, L., Soluble 3′,6-substituted indirubins with enhanced selectivity toward glycogen synthase kinase -3 alter circadian period, Journal of Medicinal Chemistry, (51), 6421-6431, 2008, 0022-2623, 1520-4804