A note on tangent bundles in a category with a ring object. G.E. Reyes, G.C. Wraith (1978) Mathematica Scandinavica
A singular Riemann-Roch for Hirzebruch characteristics Shoji Yokura (1998) Banach Center Publications
A survey of definitions of n -category. Leinster, Tom (2002) Theory and Applications of Categories [electronic only]