1. Newton CG, Ramsden CA (1982) Meso-ionic heterocycles (1976–1980). Tetrahedron 38:2965–3011
2. Gingrich HL, Baum JS (1986) Mesoionic oxazoles. In: Turchi IJ (ed) Oxazoles, the chemistry of heterocyclic compounds, vol 45. Wiley, New York
3. Ollis WD, Stanforth SP, Ramsden CA (1985) Heterocyclic mesomeric betaines. Tetrahedron 41:2239–2329
4. Huisgen R (1984) In: Padwa A (ed) 1,3-Dipolar cycloaddition chemistry, vol 1. Wiley, New York
5. Potts KT (1984) In: Padwa A (ed) 1,3-Dipolar cycloaddition chemistry, vol 2. Wiley, New York