Doina guitars were made in Bucharest, Romania. The Doina Engineering Factory in Bucharest was founded in the interwar period and was active until the 1980s. Doina made pianos, drums, accordions, wind instruments and various stringed instruments including guitars. A Doina is also a type of vocal improvised lyrical folk song unique to Romania -  coincidentally Hora the other main Romanian brand was named after a traditional folk dance.

Source: Ebay Doina guitar auction.