@article{10_4064_fm_152_2_117_150,
     author = {Christopher K. McCord},
     title = {A {Nielsen} theory for intersection numbers},
     journal = {Fundamenta Mathematicae},
     pages = {117--150},
     publisher = {mathdoc},
     volume = {152},
     number = {2},
     year = {1997},
     doi = {10.4064/fm-152-2-117-150},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-152-2-117-150/}
}