@article{10_4153_CMB_1994_046_1,
     author = {Bre\v{s}ar, Matej and \v{S}emrl, Peter},
     title = {Normal-Preserving {Linear} {Mappings}},
     journal = {Canadian mathematical bulletin},
     pages = {306--309},
     year = {1994},
     volume = {37},
     number = {3},
     doi = {10.4153/CMB-1994-046-1},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1994-046-1/}
}