《元史·本纪·卷十六》
二十日，敕令： 屯田官以三年作为任期届满，在各屯内互相调用。 
丙戌，敕： 屯田官以三岁为满，互于各屯内调用。 
On the 20th day, the Emperor ordered that the officials in charge of military cultivation should be reassigned within the military settlements after a three-year term.