... a); R. Huisgen; ,in: A. Padwa (Ed.), 1,3-Dipolar Cycloaddition Chemistry, Vol. 1, John Wiley & Sons, New York (1984), p. 1. ... Heine, RE Peavy; Tetrahedron Lett. (1965), pp. 3123–3126. ... Szeimies, H. Huber; Tetrahedron Lett. (1966), pp. 397–404. ...