Official gazette.
Electrical, mechanical, civil, chemical, geodetic, sanitary and agricultural engineering laws in the Philippines and related laws
National internal revenue code of 1977, with annotations and implementing regulations
Civil law, civil code annotated civil code of the Philippines, Republic act No. 386
The dangerous drugs act of 1972 Rep. Act no. 6425, as amended by P.D. Nos. 44, 1675, 1683, 1708, Batas Pambansa Blg. 179.
Republic Act No. 7160 'an act providing for a local government code of 1991.'.
The revised Rules of Court in the Philippines : evidence as amended by Supreme Court resolution dated March 14, 1989 - Bar Matter No. 411 Part 1, rules 128-130 ( general provisions to character evidence)