Tolgahan Cogulu & Sinan Cem Eroglu - Microtonal Guitar Duo - Amazon.com Music
Microtonal Guitar for standard guitar with added frets Vol.I by Fernando Perez & Tolgahan Çogulu (ebook/PDF & audios) - Fernando Perez World Music for Guitar
Tolgahan Çoğulu - Miami International GuitART Festival
Microtonal Guitar” Suitable for Polyphonic Music (May 8, 2015) | Boğaziçi University Alumni Office Global Outreach Program
Microtonal Guitar (Fixed Fret) by Tolgahan Çoğulu | This is Classical Guitar
Turkish musician, son's Lego Microtonal Guitar makes waves | Daily Sabah
Microtonal Guitar (Adjustable) - Tolgahan Çoğulu - Part 2 - Just Intonation - Pythagorean - Meantone - YouTube