Kettunen, K., M. Koistinen, and J. Kervinen. “Ground Truth OCR Sample Data of Finnish Historical Newspapers and Journals in Data Improvement Validation of a Re-OCRing Process”. LIBER Quarterly: The Journal of the Association of European Research Libraries, vol. 30, no. 1, Feb. 2020, pp. 1-20, doi:10.18352/lq.10322.