@article{10_4064_aa_49_4_313_322,
     author = {R. Balasubramanian and K. Ramachandra},
     title = {On the number of integers n such that nd(n) \ensuremath{\leq} x},
     journal = {Acta Arithmetica},
     pages = {313--322},
     publisher = {mathdoc},
     volume = {49},
     number = {4},
     year = {1987},
     doi = {10.4064/aa-49-4-313-322},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa-49-4-313-322/}
}