Cytotoxic Triterpenoids from the Leaves of Euphorbia pulcherrima - Smith-Kielland, I; Dornish, J M; Malterud, K E; Hvistendahl, G; Rømming, Chr; Bøckmann, O C; Kolsaker, P; Stenstrøm, Y; Nordal, A (Planta Medica, 1996)