See Raymond A. Esthus, "The Taft-Katsura Agreement - Reality or Myth?" Journal of Modern History 1959 31(1): 46-51 in JSTOR; and Jongsuk Chay, "The Taft-Katsura Memorandum Reconsidered," Pacific Historical Review, Vol. 37, No. 3 (Aug., 1968), pp. 321-326 in JSTOR
