@article{26342, author = {{Mraz, M. and Sperling, Jan and Vogel, W. and Hage, B.}}, issn = {{1050-2947}}, journal = {{Physical Review A}}, title = {{{Witnessing the degree of nonclassicality of light}}}, doi = {{10.1103/physreva.90.033812}}, year = {{2014}}, }