Norm inequalities for derivatives and differences /

by Kwong, Man Kam 1947-, Kwong, Man Kam 1947-, Zettl, Anton
Published 1964

The deficiency index problem for powers of ordinary differential expressions /

by Kauffman, Robert McKenzie 1941-, Kauffman, Robert McKenzie 1941-, Zettl, Anton, Read, Thomas Thorton 1943-
Published 1964