@book{150217,
	author = {Drilling and Completion Committee and Petroleum Industry Training Sevice (PITS)},
	title = {Ground disturbance in the vicinity of buried facilities (last updated march 28, 2003)},
	publisher = {Petroleum Industry Training Service (PITS)},
	year = {2002},
	address = {Calgary, Alberta},
	note = {Sitio web visitado en julio de 2003 ; El texto completo del documento está disponible en PDF},
	url = {http://www.psc.ca/manuals/pdffiles/irpvol_17.pdf}
}