Holton, D. A., & Sheehan, J. (1993). The Petersen graph. Cambridge University Press.
Lua i Stíl Chicago (17ú heag.)Holton, Derek Allan, agus J. Sheehan. The Petersen Graph. Cambridge: Cambridge University Press, 1993.
Lua MLA (9ú heag.)Holton, Derek Allan, agus J. Sheehan. The Petersen Graph. Cambridge University Press, 1993.
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