LEVENS, A. S. (1962). Graphics: With an introduction to conceptual design. John Wiley & Sons.
Lua i Stíl Chicago (17ú heag.)LEVENS, Alexander S. Graphics: With an Introduction to Conceptual Design. John Wiley & Sons, 1962.
Lua MLA (8ú heag.)LEVENS, Alexander S. Graphics: With an Introduction to Conceptual Design. John Wiley & Sons, 1962.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.