There are many diminutive forms of Georgi in Bulgarian, however, neither Geno, nor Ge(n)ko are among them. The most widely used diminutives include Joro and Gogo.
Georgi Plekhanov was a Russian revolutionary, philosopher and Marxist theoretician. He was a founder of the social-democratic movement in Russia and was one of the first Russians to identify himself as "Marxist".
The Bulgarian wrestler in classic style Georgi Murkov. For the period - the autumn of 1971-the autumn of 1972 - he has become European, World and Olympic Champion!
The Bulgarian physicist-academic Georgi Nadjakov found the first Bulgarian discovery of scientific significance - the photo-electric state of matter - which received international recognition in the late 1930s. Photocopying and certain types of memory-storing devices are based on this important discovery!