@article{10_4153_CJM_1976_094_9,
     author = {Brownawell, W. Dale},
     title = {The {Algebraic} {Independence} of {Certain} {Exponential} {Functions}},
     journal = {Canadian journal of mathematics},
     pages = {968--976},
     year = {1976},
     volume = {28},
     number = {5},
     doi = {10.4153/CJM-1976-094-9},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-094-9/}
}