Panzer A, Joubert AM, Eloff JN, Albrecht CF, Erasmus E, Seegers JC (November 2000). "Chemical analyses of Ukrain, a semi-synthetic Chelidonium majus alkaloid derivative, fail to confirm its trimeric structure". Cancer Letters. 160 (2): 237–41. doi:10.1016/s0304-3835(00)00595-4. PMID11053654.
Panzer A, Joubert AM, Eloff JN, Albrecht CF, Erasmus E, Seegers JC (November 2000). "Chemical analyses of Ukrain, a semi-synthetic Chelidonium majus alkaloid derivative, fail to confirm its trimeric structure". Cancer Letters. 160 (2): 237–41. doi:10.1016/s0304-3835(00)00595-4. PMID11053654.