As a signatory to Berne, Greece is required to allow certain fair uses in accordance with Article 10. Paragraph 1 states...
(1) It shall be permissible to make quotations from a work which has already been lawfully made available to the public, provided that their making is compatible with fair practice, and their extent does not exceed that justified by the purpose, including quotations from newspaper articles and periodicals in the form of press summaries.
Paragraph 2, however, allows each signatory to make its own laws on fair use for educational purposes. The Hellenic Copyright Organization (OPI) offers a complete list of exceptions on their website below.