@article{10_4153_CMB_2011_089_1,
     author = {Nie, Zhaohu},
     title = {On {Sha's} {Secondary} {Chern{\textendash}Euler} {Class}},
     journal = {Canadian mathematical bulletin},
     pages = {586--596},
     year = {2012},
     volume = {55},
     number = {3},
     doi = {10.4153/CMB-2011-089-1},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2011-089-1/}
}