Hoesch, L., Bieri, JH., Declercq, J.-P., Germain, G., & Vanmeerssche, M. (1981). Crystal-structure of (z)-1-phenyl-2-phthalimido-diazene-1-oxide and of (z)-1-dimethylamino-2-phthalimido-diazene-1-oxide. Helvetica Chimica Acta, 64(3), 905-914. https://doi.org/10.1002/hlca.19810640327 (Original work published 1981)