@article{BMMS_2013_36_4_a8,
     author = {Hyunjin Lee and Seonhui Kim},
     title = {Hopf {Hypersurfaces} with $\eta${-Parallel} {Shape} {Operator} in {Complex} {Two-Plane} {Grassmannians}},
     journal = {Bulletin of the Malaysian Mathematical Society},
     year = {2013},
     volume = {36},
     number = {4},
     url = {http://geodesic.mathdoc.fr/item/BMMS_2013_36_4_a8/}
}