@article{10_4153_CMB_2014_060_x,
     author = {Yang, Dachun and Yang, Sibei},
     title = {Second-order {Riesz} {Transforms} and {Maximal} {Inequalities} {Associated} with {Magnetic} {Schr} \"odinger {Operators}},
     journal = {Canadian mathematical bulletin},
     pages = {432--448},
     year = {2015},
     volume = {58},
     number = {2},
     doi = {10.4153/CMB-2014-060-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2014-060-x/}
}