Library of Congress. Federal Research Division & Curtis, G. E. (1993). Bulgaria: A country study (2nd ed.). Federal Research Division, Library of Congress : For sale by the Supt. of Docs., U.S. G.P.O..
Citação norma ChicagoLibrary of Congress. Federal Research Division and Glenn E. Curtis. Bulgaria: A Country Study. 2nd ed. Washington, D.C.: Federal Research Division, Library of Congress : For sale by the Supt. of Docs., U.S. G.P.O., 1993.
Citação norma MLALibrary of Congress. Federal Research Division and Glenn E. Curtis. Bulgaria: A Country Study. 2nd ed. Federal Research Division, Library of Congress : For sale by the Supt. of Docs., U.S. G.P.O., 1993.
Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.