1. W. Carruthers , Some Modern Methods of Organic Synthesis, Cambridge University Press, Cambridge, second edn, 1978
2. W. Carruthers , Cycloaddition Reactions in Organic Synthesis, Pergamon, Oxford, 1990
3. A. Wasserman , Diels-Alder Reactions, Elsevier, New York, 1965
4. A. Padwa , 1,3-Dipolar Cycloaddition Chemistry, Wiley-Interscience, New York, 1984, vols. 1-2
5. D. L. Boger , S.M. Weinred and H. H.Wasserman, Hetero Diels-Alder Methodology in Organic Chemistry, Academics, New York, 1987