M. Wagner, B. Vicinus, S. Muthra, T. Richards, R. Linder, V. O. Frick, A. Groh, C. Rubie and F. Weichert, "Text Mining, A Race Against Time? An Attempt to Quantify Possible Variations in Text Corpora of Medical Publications Throughout the Years" , Computers in Biology and Medicine, vol. 73, pp. 173-185, 2016.