George M Martynuk Inc (GMM Inc.) is an innovative artists management firm offering both Worldwide Public Relations and World Wide Management for Opera Singers.

Opera star Markella Hatziano is represented in the U.S. by the worldwide public relations and artists management firm George M Martynuk Inc.

MARKELLA NET is a global network of websites dedicated to the music, performances, recordings and career of the multi-dimensional Greek opera star Markella Hatziano.