@article{10_4171_ggd_300,
     author = {Aditi Kar and Nikolay Nikolov},
     title = {Rank gradient and cost of {Artin} groups and their relatives},
     journal = {Groups, geometry, and dynamics},
     pages = {1195--1205},
     year = {2014},
     volume = {8},
     number = {4},
     doi = {10.4171/ggd/300},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/300/}
}