Não informado. (1975). Geodesy. Bulgarian Academy of Sciences.
Lua i Stíl Chicago (17ú heag.)Não informado. Geodesy. Sofia: Bulgarian Academy of Sciences, 1975.
Lua MLA (8ú heag.)Não informado. Geodesy. Bulgarian Academy of Sciences, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.