International Critical Tables is the result of the cooperative labors of a large number of specialists, each of whom
has been charged with the responsibility for the critical compilation of the quantitative information available on his topic. The
word "critical" in this connection means that the Cooperating Expert was requested to give in each instance the "best" value
which he could derive from all the information available, together, where possible, with an indication of its probable reliability.
Through a cooperative arrangement with International Annual Tables, the Board of Editors has been able to place in
the hands of each Cooperating Expert the literature references belonging to his topic for the years 1910-1923 inclusive, as
compiled by the staff of International Annual Tables. For the period preceding 1910, each Cooperating Expert was directed to
collect the necessary literature references from the various published handbooks, special treatises, works of reference, and
other sources known to him as a specialist in the field. No attempt has been made to systematically cover the literature since
1923, although a certain amount of information published since then has been utilized.