@article{10_4064_aa136_3_4,
     author = {Christian Krattenthaler and Igor Rochev and Keijo V\"a\"an\"anen and Wadim Zudilin},
     title = {On the non-quadraticity of values
 of the $q$-exponential function and related $q$-series},
     journal = {Acta Arithmetica},
     pages = {243--269},
     publisher = {mathdoc},
     volume = {136},
     number = {3},
     year = {2009},
     doi = {10.4064/aa136-3-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa136-3-4/}
}