Sŭdbata na t︠s︡arskite sluzhiteli v epokhata na sot︠s︡ializmaPetko Mangachev · First published 2021Open the Tome
Dokumentalna istorii͡a na ruskite bezhant͡si v Bŭlgarii͡aPetko Mangachev · First published 2015Open the Tome
Zagadkite v upravlenieto na t︠s︡ar Boris III v perioda 1.III.1941 g.--28.VIII.1943 g.Petko Mangachev · First published 2015Open the Tome
Ukrainskata emigrat︠s︡ii︠a︡ v Bŭlgarii︠a︡ prez perioda mezhdu dvete svetovni voǐniPetko Mangachev · First published 2011Open the Tome
D-r Nikolaĭ Nikolaev -- zhivot i delo, (1887 g.--1960 g.)Petko Mangachev · First published 2007Open the Tome
Moskva po pŭti︠a︡ na preustroĭstvotoPetko Mangachev, Ivan Zakhariev · First published 1988Open the Tome
Vŭvezhdaneto na novata sistema ot osnovni zaplati--delo na trudovite kolektiviDimitŭr Shopov, Petko Mangachev · First published 1988Open the Tome
Dukhovnoto razvitie na trudovii︠a︡ kolektiv--uskoritel na intenzifikat︠s︡ii︠a︡Petko Mangachev · First published 1986Open the Tome
I͡U︡zhna Korei͡a︡ v agresivnata strategii͡a︡ na SAShtPetko Mangachev · First published 1984Open the Tome
Revoli︠u︡t︠s︡ii︠a︡ta i sot︠s︡ialisticheskoto obshtestvo v Bŭlgarii︠a︡Dobrin Michev, Petko Mangachev · First published 1984Open the Tome
Sofii͡a︡ ozarena ot zhivotvornata bŭlgaro-sŭvetska druzhbaPetko Mangachev · First published 1984Open the Tome
