Definition of "Manchoukuo"

When evacuation was effected it would be “to the Great Wall”, not to the Jehol boundary. Since the Great Wall dips well into northern Hopei, an area of several thousand square miles was thus added to the territory of Manchoukuo.[...]In actual operation, the cordon sanitaire of the “demilitarized” zone was far from reciprocal. Under the terms of the Tangku Truce, Chinese armed opposition to Manchoukuo was clearly prevented.

1938, T. A. Bisson, Japan in China‎, New York: Macmillan Company, pages 46–47

An extensive alternation of the Manchoukuo Government's project for the establishment of a gigantic State-owned hydroelectric power-house near the Chingpo Lake in Mutankiang Province, is recommended in an official report just submitted by the party of experts which was recently dispatched to the spot to conduct further investigations into the project.

1938 April, “Chingpo Power Project Revised”, in The Far Eastern Review‎, volume XXXIV, number 4, Shanghai, page 151, column 2

The truce of May 1933 established a modus vivendi that was in effect a treaty of peace and that tacitly (although not explicitly) acquiesced in the Japanese occupation of Manchuria. The articulate among the Chinese, however, remained unreconciled to the existence of Manchoukuo. Moreover, for a number of years only two foreign powers besides Japan, (Italy and El Salvador) formally recognized the new state.Japan, however, preserved in consolidating its position in Manchoukuo.

1968, “CHINA”, in Encyclopedia Britannica, volume 5, page 593, column 2