Beilby, M. H. (1975). Economics and operational research. ELSEVIER.
Lua i Stíl Chicago (17ú heag.)Beilby, M. H. Economics and Operational Research. ELSEVIER, 1975.
Lua MLA (8ú heag.)Beilby, M. H. Economics and Operational Research. ELSEVIER, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.