K. Alder, H.f. Ricker, Ann., 524, 180(1936)
K. Alder in Newer Methods of Preperative Organic Chemistry, English, Ed. (Interscience, New York, 1948), p. 471
A.C. Cope, A.C. Haven, Jr., F.L. Ramp, E.R. Trumbull, J. Am. Chem. Soc. 74, 4867(1952);