@article{10_4064_fm217_3_3,
     author = {Kai Ishihara and Atsushi Ishii},
     title = {An operator invariant for handlebody-knots},
     journal = {Fundamenta Mathematicae},
     pages = {233--247},
     publisher = {mathdoc},
     volume = {217},
     number = {3},
     year = {2012},
     doi = {10.4064/fm217-3-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm217-3-3/}
}