@article{10_2307_121114,
     author = {H. Alexander and John Wermer},
     title = {Linking numbers and boundaries of varieties},
     journal = {Annals of mathematics},
     year = {2000},
     volume = {151},
     number = {1},
     doi = {10.2307/121114},
     zbl = {1013.32007},
     url = {http://geodesic.mathdoc.fr/articles/10.2307/121114/}
}