Sources for these statistical reports include the Internet Archive, Hathitrust Digital Library, Project Gutenberg and personal files. They include a compilation of a series of articles published by the Winnipeg Free Press in 1912. Also, there are two doctoral theses, one published in 1923 by Harold Innis and another published in 1931 by Heinz Kuhn. In 1946, CPR published a revised handbook to the Company and in 1948, the Dominion Bureau of Statistics published a statistical compliation on the CPR for the years 1923 to 1948.