C. F. Crocker to CPH, June 18, July 12, 1890 CPH Papers, ser. 1, r. 48.

C. F. Crocker to CPH, Nov. 9, 1891 CPH Papers, r. 50.

CPH to W. H. Mills, July 6, 1892 CPH Papers, vol. 228, ser. 2, r. 33.