@article{CM_1959-1960__14__71_0,
     author = {Foia\c{s}, Ciprian},
     title = {On {Hille's} spectral theory and operational calculus for semi-groups of operators in {Hilbert} space},
     journal = {Compositio Mathematica},
     pages = {71--73},
     publisher = {Kraus Reprint},
     volume = {14},
     year = {1959-1960},
     mrnumber = {105027},
     zbl = {0086.31903},
     language = {en},
     url = {http://archive.numdam.org/item/CM_1959-1960__14__71_0/}
}