@article{oai:tsukuba.repo.nii.ac.jp:00015832,
 author = {Omachi, Eriko},
 issue = {2},
 journal = {Tsukuba Journal of Mathematics},
 month = {Dec},
 pages = {495--503},
 title = {Some inequalities on |nabla R|, |nabla Ric| and |dr| in Riemannian manifolds},
 volume = {13},
 year = {1989}
}