1. Lloyd, D., in: Organic chemistry (series 1), aromatic compounds, p. 179. London: Butterworths 1973.
2. It was suggested by Agranat, I., and Bergmann, E. D.: Tetrahedron Lett. 1966, 2373, to use the name “triafulvene” for methylene cyclopropenes as well as for cyclopropenones and their functional derivatives. In this article, the term “triafulvene” is restricted to methylene cyclopropene.
3. Krebs, A. W.: Angew. Chem. 77, 10 (1965); Angew. Chem. Int. Ed. Engl. 4, 19 (1965).
4. Wendisch, D. in: Methoden der organischen Chemie (Houben-Weyl-Müller) Bd. IV/3, S. 729. Stuttgart: Georg Thieme Verlag 1971.
5. Lloyd, D. in: Carbocyclic/Von-benzenoid Aromatic Compounds, p. 24. Amsterdam-London-New York: Elsevier Publishing Company 1966.