1. On the field of values subordinate to a norm;Bauer;Numer. Math.,1962
2. Extensions of Jentzsch's theorem;Birkhoff;Trans. Amer. Math. Soc.,1957
3. Geometrical properties of the unit sphere of Banach algebras;Bohnenblust;Ann. of Math.,1955
4. Numerical ranges of operators and of elements of normed algebras;Bonsall;London Math. Soc., Lecture Note Series 2,1971
5. An Introduction to Diophantine Approximation;Cassels,1965