@article{JRAM_1977__291_151858,
     author = {Robert F. Olin and James E. Thomson},
     title = {Limacons, normal operators and polar factorizations.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {133--144},
     publisher = {mathdoc},
     volume = {291},
     year = {1977},
     zbl = {0353.47011},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1977__291_151858/}
}