Kirkman, Th. P. (1856), "On the enumeration of x-edra having triedral summits and an (x − 1)-gonal base", Philosophical Transactions of the Royal Society of London: 399–411, doi:10.1098/rstl.1856.0018, JSTOR108592.
Kirkman, Th. P. (1856), "On the enumeration of x-edra having triedral summits and an (x − 1)-gonal base", Philosophical Transactions of the Royal Society of London: 399–411, doi:10.1098/rstl.1856.0018, JSTOR108592.