@article{10.30755/NSJOM.04217,
     author = {Luong Quoc Tuyen},
     title = {A partial answer to a question of {Y.} {Ikeda,} {C.} {Liu} and {Y.} {Tanaka}},
     journal = {Novi Sad Journal of Mathematics},
     pages = {63 - 68},
     publisher = {mathdoc},
     volume = {47},
     number = {1},
     year = {2017},
     doi = {10.30755/NSJOM.04217},
     url = {http://geodesic.mathdoc.fr/articles/10.30755/NSJOM.04217/}
}