A study ordered by commissioners in Harris County , which includes Houston , found that about one-fifth of the patients in its health system last year were immigrants without documents , most of them from Mexico .
Harris County /location/location/contains Houston
DT NN VBN IN NNS IN NNP NNP , WDT VBZ NNP , VBD IN IN NN IN DT NNS IN PRP$ NN NN JJ NN VBD NNS IN NNS , JJS IN PRP IN NNP .
Harris County
LOCATION
Houston
LOCATION
/location/location/contains