@article{10_4064_ap_51_1_303_312,
     author = {F. H. Szafraniec},
     title = {Kato-Protter type inequalities, bounded vectors and the exponential function},
     journal = {Annales Polonici Mathematici},
     pages = {303--312},
     publisher = {mathdoc},
     volume = {51},
     number = {1},
     year = {1990},
     doi = {10.4064/ap-51-1-303-312},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-51-1-303-312/}
}