Decree No.55-CP of May 28, 1997 on the establishment of townships of Yen Lap, Ha Hoa, Tam Thanh, Phong Chau and Thanh Son districts, Phu Tho province.

To establish Yen Lap township of Yen Lap district on the basis of the whole land area of 1,196.49 hectares and a population of 5,904 of Tan Long commune.

To establish Ha Hoa township of Ha Hoa district on the basis of the whole land area of 1,002.85 hectares and a population of 7,060 of Am Thuong commune.

To establish Hung Hoa township of Tam Thanh district on the basis of a land area of 453.38 hectares and a population of 4,391 of Hung Hoa commune.

To establish Lam Thao township of Phong Chau district on the basis of the whole land area and a population of Cao Mai commune, plus a land area of 7.3 hectares and a population of 734 of Chu Hoa commune.

To establish Phu Ho township of Phong Chau district on the basis of the whole land area of 1,616 hectares and a population of 11,076 of Phu Ho commune.

To establish Thanh Son township of Thanh Son district on the basis of a land area of 290 hectares and a population of 9,894 of Son Hung commune, and a land area of 125 hectares inhabited by 2,686 people of Thuc Luyen commune.- (Summary)