[1] S. EILENBERG G. M. KELLY: Closed categories. Proc. Conf. Categorical Algebra (La Jolla, Calif., 1965), pp. 421-562. Springer, New York, 1966. MR 0225841
[2] G. M. KELLY S. MacLANE: Coherence in closed categories. J. Pure Appl. Algebra 1 (1971), 97-140. MR 0283045