ref.bib

@booklet{volaya,
	author 		=	"Olaya, Víctor",
	title		=	"Sistemas de Información Geográfica",
	publisher	=	"CreateSpace Independent Publishing Platform",
	year		=	"2014",
	url			=	"https://volaya.github.io/libro-sig/",
}

@book{gvaliente,
	author 		= 	"Valiente, Gabriel",
	title 		= 	"Algorithms on Trees and Graphs",
	isbn 		= 	"3540435506",
	publisher 	= 	"Springer",
	year 		= 	"2002",
}

@book{ewestra,
	author		=	"Westra, Erik",
	title		=	"Python Geospatial Development (3rd Edition)",
	isbn		=	"9781785288937",
	publisher	=	"Packt",
	year		=	"2016",
}

@book{bolstad,
	author		=	"Bolstad, Paul",
	title		=	"GIS Fundamentals: A first text on geographic information systems",
	edition		= 	4,
	isbn		=	"9780971764736",
	publisher	=	"AtlasBooks",
	year		=	"2012",
}

@book{roswell,
	author		=	"Roswell, Charles",
	editor		=	"Kresse, Wolfgang and Danko, David M.",
	title		=	"Modeling of Geographic Information",
	year		=	"2012",
	publisher	=	"Springer Berlin Heidelberg",
	address		=	"Berlin, Heidelberg",
	isbn		=	"978-3-540-72680-7",
	doi			=	"10.1007/978-3-540-72680-7",
	url			=	"https://doi.org/10.1007/978-3-540-72680-7",
}

@book{obehsu,
	author		=	"O. Obe, Regina and S. Hsu, Leo",
	title		=	"PostGIS in Action",
	edition		=	2,
	isbn		=	"9781617291395",
	publisher	=	"Manning Publications",
	year		=	"2015"
	
}