Here you can find some useful links:
- Cyprus Mathematical Society, http://www.cms.org.cy
- Hellenic Mathematical Society, http://www.hms.gr
- Romanian Mathematical Society, http://rms.unibuc.ro/
- Bulgarian Mathematical Society, http://www.math.bas.bg/talents/
- Turkish Mathematical Society, http://www.tmd.org.tr/?lang=en
- Nesin Mathematics Village in Turkey, https://matematikkoyu.org/eng/