(1973). Philosophy and sciene ; Morality and culture ; Technology and man. Sofia Pr..
Lua i Stíl Chicago (17ú heag.)Philosophy and Sciene ; Morality and Culture ; Technology and Man. Sofia: Sofia Pr., 1973.
Lua MLA (8ú heag.)Philosophy and Sciene ; Morality and Culture ; Technology and Man. Sofia Pr., 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.