A remark on p-integral and p-absolutely summing operators form l u into l v B. Carl — 1976 Studia Mathematica
Entropy numbers of operators in Banach spaces Carl, B.; Pietsch, A. — 1977 General topology and its relations to modern analysis and algebra IV
On the cohomology of smooth manifolds. Carl B. Allendorfer; James, Jr. Eells Commentarii mathematici Helvetici