This research dissertation aims to analyze from a quantitative point of view the use of the documentary sources in local news of Spanish newspapers related to the Region of Valencia between 2006 and 2010.	

In order to study in depth the use of these sources in the local news, the most significant and widely circulated newspapers during the year 2006 have been chosen, according to the O.J.D. These are: 	El País Comunidad Valenciana, El Mundo Valencia, Levante-EMV and Las Provincias.

In order to accomplish this task, a theoretical base explaining the role of the documentation services in the journalistic activity as well as the required premises of the journalists in documentary terms to fulfill their labour has been presented. Next, the concept and typology of the information sources from a documentary point of view have been investigated.

Once the media were selected, the next step was to establish the study cases. In order to accomplish this task, real events represented by a set of news related to the Region of Valencia and published at least in three of the four most representative newspapers were chosen.

The news has been selected on a seven day week basis. The study core is constituted by three groups of news. The first group for newspapers printed between year 2006 and 2007, the second group embraces the newspapers printed in the same months between 2009 and 2010 and the third group, both for the printed and for the digital edition of these newspapers during the same months between year 2009 and 2010.

Once the core was established, the information sources of the news were identified and quantified and afterwards classified according to different criteria designed for this task.	

Once the quantitative evaluation has been conducted the most significant instances of the study cases have been described. Then, two comparisons based on the three resulting sets have been conducted. The first evaluates the results obtained from the first couple of sets and showing the evolution in the use of information sources in a period of three years, and the second, evaluating the use of information sources between printed newspapers and their digital editions.

Once the use of the information sources of the news was analyzed, the study reveals very interesting results about the use of these sources in the construction of the news, the role of the documentation centers in this subject and the evolution of the use of these sources from year 2006 to 2010 both for printed and digital papers.