The Special Issues of Tbilisi Mathematical Journal are fully refereed international publications, publishing original research papers in all areas of pure and applied mathematics. The editors are well known experts in the field, particularly from leading universities of USA and Europe. Papers should satisfy high standards and only works of high quality are recommended for publication. They constitute a collection around selected themes related to mathematical sciences, or coming from a specific group of mathematicians or event, or coming from a workshop, symposia and international mathematical conferences.