A. C. Bassett to CPH, May 8, 1891, C. Crocker to CPH, June 30, 1891, W. H. Mills to CPH, July 10, 1891, CPH Papers, ser. 1, r. 49.
W. H. Mills to CPH, June 30, 1892, CPH Papers, ser. 1, r. 51.
CPH to Mills, Jan. 9, 1892, Jan. 11, 1892, CPH Papers, ser. 1, r. 50.
Mahl, Memoirs, Southern Pacific Co., F-1, Mahl Papers.
Mahl, Memoirs, Southern Pacific Co., F-1, Mahl Papers.