PNP MEMO CIRCULAR NO. 2011-026<SUP STYLE="COLOR: RGB(255, 0, 0);">*</SUP>, October 24, 2011
GENERAL GUIDELINES IN THE CONDUCT OF PRODUCT TEST, POST QUALIFICATION TEST, FUNCTIONAL TEST AND EVALUATION FOR VARIOUS TYPES OF AIR TRANSPORTATION
National Administrative Register October 24, 2011
<SUP STYLE=”COLOR: RGB(255, 0, 0);”>*</SUP> Text Available at Office of the National Administrative Register, U.P. Law Complex, Diliman, Quezon City.