TY  - BOOK
AU  - Butzer,Paul Leo
AU  - Berens,Hubert
TI  - Semi-groups of operators and approximation
U1  - 517.7 
PY  - 1967///
CY  - Berlin
PB  - Springer
KW  - Banach spaces
KW  - Semigroups of operators
KW  - Approximation theory
KW  - Group theory
N1  - Includes index; Bibliography: p. 295-313
ER  -