CPH to Manvel, Sept. 24, 1890, CPH Papers, ser. 1, r. 48.
CPH to Manvel, June 19, 1891, Michael Grogan to CPH, June 7, 1891, CPH Papers, ser. 1, r. 49.
William Morse Cole, Accounts: Their Construction and Interpretation, for Business Men and Students of Affairs (Boston: Houghton Mifflin, 1915, orig. ed. 1908).
William Morse Cole, Accounts: Their Construction and Interpretation, for Business Men and Students of Affairs (Boston: Houghton Mifflin, 1915, orig. ed. 1908), 237-238.
Speyer & Co. to CPH, May 14, 1883, CPH Papers, ser. 1, r. 32.
Speyer Brothers to CPH, Sept. 1, 1883, CPH, ser. 1, r. 33.