@article{10_4064_sm225_2_3,
     author = {Mohammad Ali Ardalani},
     title = {Numerical index with respect to an operator},
     journal = {Studia Mathematica},
     pages = {165--171},
     year = {2014},
     volume = {225},
     number = {2},
     doi = {10.4064/sm225-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm225-2-3/}
}