AN ASSESSMENT OF WATER QUALITY (NH4+, NO2-, NO3-, TP, SO4, COLIFORM BACTERIA AND HEAVY METALS) OF THE MAIN WATER SUPPLIES IN THE STATE OF CAMPECHE oleh Jorge Arturo Benitez, Maurilio Lara-Flores, Victor Manuel Osorio, Leonel Amabilis, Joshua Ben-Arie, Jaime Rendon, Jimmy Vidal-Maldonado, Brenda Trinidad Cen-Poot, Karina Sonda-Santos