@article{10_1017_S0017089500006509,
     author = {Rako\v{c}evi\'c, Vladimir},
     title = {Approximate point spectrum and commuting compact perturbations},
     journal = {Glasgow mathematical journal},
     pages = {193--198},
     year = {1986},
     volume = {28},
     number = {2},
     doi = {10.1017/S0017089500006509},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500006509/}
}