@article{10_4064_aa_87_1_67_78,
     author = {Oto Strauch and J\'anos T\'oth},
     title = {Asymptotic density of {A\ensuremath{\subset}} {\ensuremath{\mathbb{N}}} and density of the ratio set {R(A)}},
     journal = {Acta Arithmetica},
     pages = {67--78},
     publisher = {mathdoc},
     volume = {87},
     number = {1},
     year = {1998},
     doi = {10.4064/aa-87-1-67-78},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-87-1-67-78/}
}