Structure/activity relationships of the genotoxic potencies of sixteen pyrrolizidine alkaloids assayed for the induction of somatic mutation and recombination in wing cells of Drosophila melanogaster - Frei, H; Lüthy, J; Brauchli, J; Zweifel, U; Würgler, F E; Schlatter, C (Chem Biol Interact, 1992)