@article{10_4064_cm_30_2_259_267,
     author = {L. F. Lam},
     title = {Invariant functions for positive operators on normed {K\"othe} spaces},
     journal = {Colloquium Mathematicum},
     pages = {259--267},
     publisher = {mathdoc},
     volume = {30},
     number = {2},
     year = {1974},
     doi = {10.4064/cm-30-2-259-267},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-30-2-259-267/}
}