Accessibility Issues in Digital Mathematical Libraries

The growing number of digital libraries does not serve only metadata of scientific or educational documents, but also the full-text data themselves. This brings new possibilities but also accessibility issues to cope with when designing user interfaces for exploratory search and accessing and reading the full-texts that are usually provided only in some version of PDF format. We have participated in the design and solutions for the European Digital Mathematics Library (EuDML) and also participated in the preparation of primary data of the Czech Digital Mathematics Library (DML-CZ). In the paper we describe the developed technologies addressing Braille output of document content including mathematical formulae, document preprocessing and enhancement that increase accessibility, readability and exploration qualities (similarity of mathematical documents) of the documents in digital libraries of texts for tertiary education and research in STEM domain.