@article{10_1017_S0017089514000536,
     author = {TANIGUCHI, TETSUYA and UDAGAWA, SEIICHI},
     title = {CHARACTERIZATIONS {OF} {RICCI} {FLAT} {METRICS} {AND} {LAGRANGIAN} {SUBMANIFOLDS} {IN} {TERMS} {OF} {THE} {VARIATIONAL} {PROBLEM}},
     journal = {Glasgow mathematical journal},
     pages = {643--651},
     year = {2015},
     volume = {57},
     number = {3},
     doi = {10.1017/S0017089514000536},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089514000536/}
}