Collingwood, E. F. (1966). The theory of cluster sets. Cambridge University Press.
Lua i Stíl Chicago (17ú heag.)Collingwood, Edward F. The Theory of Cluster Sets. Cambridge: Cambridge University Press, 1966.
Lua MLA (9ú heag.)Collingwood, Edward F. The Theory of Cluster Sets. Cambridge University Press, 1966.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.