Piotrowski, R. (1978). Cartels and trusts: Their origin and historical development from the economic and legal aspects. Porcupine Press.
Lua i Stíl Chicago (17ú heag.)Piotrowski, Roman. Cartels and Trusts: Their Origin and Historical Development from the Economic and Legal Aspects. Philadelphia: Porcupine Press, 1978.
Lua MLA (9ú heag.)Piotrowski, Roman. Cartels and Trusts: Their Origin and Historical Development from the Economic and Legal Aspects. Porcupine Press, 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.