Salud, J. P. (2014). Ecoshield's engineered sanitary landfill: Technology whose time has come. Philippine Graphic.
Chicago-referens (17:e uppl.)Salud, Joel Pablo. "Ecoshield's Engineered Sanitary Landfill: Technology Whose Time Has Come." Philippine Graphic 2014.
MLA-referens (9:e uppl.)Salud, Joel Pablo. "Ecoshield's Engineered Sanitary Landfill: Technology Whose Time Has Come." Philippine Graphic, 2014.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.