Guerch, G., Labarre, JF., Lahana, R., Sournies, F., Enjalbert, R., Galy, J., & Declercq, J.-P. (1984). Conclusive Statement of the So-called Spiro Versus Ansa Dilemma in Cyclophosphazenes for Polyamines As Polyfunctional Reagents. Inorganica Chimica Acta, 83(2), L33-L36. https://doi.org/10.1016/S0020-1693(00)82501-3 (Original work published 1984)