COWAN, H. J., & COWAN, H. J. (1981). Structural System. Van Nostrand Reinhold Company.
Lua i Stíl Chicago (17ú heag.)COWAN, Henry J., agus Henry J. COWAN. Structural System. Van Nostrand Reinhold Company, 1981.
Lua MLA (8ú heag.)COWAN, Henry J., agus Henry J. COWAN. Structural System. Van Nostrand Reinhold Company, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.