@article{oai:tsukuba.repo.nii.ac.jp:00035490,
 author = {Aikawa, Yuri and 相川, 祐理 and Furuya, Kenji and 古家, 健次 and Nomura, Hideko and Qi, Chunhua},
 issue = {2},
 journal = {The Astrophysical Journal},
 month = {Jul},
 title = {ANALYTICAL FORMULAE OF MOLECULAR ION ABUNDANCES AND THE N2H+ RING IN PROTOPLANETARY DISKS},
 volume = {807},
 year = {2015}
}