1. PDFBox. https://pdfbox.apache.org/. PDFBox. https://pdfbox.apache.org/.
2. Poppler. https://poppler.freedesktop.org/. Poppler. https://poppler.freedesktop.org/.
3. Semantic Scholar. www.semanticscholar.org. Semantic Scholar. www.semanticscholar.org.
4. Text Detection in Screen Images with a Convolutional Neural Network. https://github.com/domoritz/label_generator. Text Detection in Screen Images with a Convolutional Neural Network. https://github.com/domoritz/label_generator.