@article {1801.07539, archivePrefix = {arXiv}, eprint = {1801.07539}, primaryClass = {astro-ph.SR}, author = {M. De Simone and others}, title = {Deuterium and $^{15}$N fractionation in N$_2$H$^+$ during the formation of a Sun-like star}, year = {2018}, url = {http://arxiv.org/abs/1801.07539} }