@article{10_4064_sm_43_3_209_215,
     author = {Niels Nielsen},
     title = {On the trace of some operators},
     journal = {Studia Mathematica},
     pages = {209--215},
     publisher = {mathdoc},
     volume = {43},
     number = {3},
     year = {1972},
     doi = {10.4064/sm-43-3-209-215},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-43-3-209-215/}
}