Pearson 1904
From Genetics Wiki
Citation
Pearson, K. (1904). Mathematical Contributions to the Theory of Evolution. XII. On a Generalised Theory of Alternative Inheritance, with Special Reference to Mendel's Laws. Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character, 203(359-371), 53-86.
Links
http://rsta.royalsocietypublishing.org/content/203/359-371/53