Debruyn, A., Eeckhaut, G., Villaneuva, J., & Hannart, J. (1985). Synthesis and H-1-nmr Study of 3,4-diethyl-1,2,3,3a,4,5-hexahydro-canthinone-6. Tetrahedron, 41(23), 5553-5561. https://doi.org/10.1016/S0040-4020(01)91356-0 (Original work published 1985)