The geometry of geodesics

by Busemann, Herbert
Published 1955

Geometry of manifolds

by Bishop, Richard L.
Published 1964

The four-color problem

by Ore, Øystein
Published 1967

Dimension theory

by Nagami, Keiô
Published 1970

Critical point theory in global analysis and differential topology : an introduction

by Morse, Marston, Cairns, Stewart S.
Published 1969