@article{MM2_1993__79_1_155853,
     author = {Oleg V. Davydov},
     title = {Some condensation theorems for semigroup operators.},
     journal = {Manuscripta mathematica},
     pages = {435--446},
     publisher = {mathdoc},
     volume = {79},
     number = {1},
     year = {1993},
     zbl = {0798.47033},
     url = {http://geodesic.mathdoc.fr/item/MM2_1993__79_1_155853/}
}