Purvis, R. L. (1994). Underwater bridge maintenance and repair. National Academy Press.
Lua i Stíl Chicago (17ú heag.)Purvis, Ronald L. Underwater Bridge Maintenance and Repair. Washington, D.C: National Academy Press, 1994.
Lua MLA (9ú heag.)Purvis, Ronald L. Underwater Bridge Maintenance and Repair. National Academy Press, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.