ARNELL, A. (1963). Standard Graphical Symbols. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)ARNELL, Alvin. Standard Graphical Symbols. McGraw-Hill, 1963.
Lua MLA (8ú heag.)ARNELL, Alvin. Standard Graphical Symbols. McGraw-Hill, 1963.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.