@article{10_4153_CJM_2012_064_x,
     author = {Durand-Cartagena, E. and Ihnatsyeva, L. and Korte, R. and Szuma\'nska, M.},
     title = {On {Whitney-type} {Characterization} of {Approximate} {Differentiability} on {Metric} {Measure} {Spaces}},
     journal = {Canadian journal of mathematics},
     pages = {721--742},
     year = {2014},
     volume = {66},
     number = {4},
     doi = {10.4153/CJM-2012-064-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2012-064-x/}
}