Standard Eurobarometer 80 (autumn 2013). Public Opinion in the European Union. Spain’s National Report. European Commission.
 Although the Francoist authorities expressed little interest on institutions like the Economic Community on Coal and Steel, due to the isolation of the Spanish mining and steel industry sectors, the French initiative in 1951 to create the Agricultural European Community or “Green Pool” had a substantially different treatment. The absorption of this organization by the Organization for the European Economic Co-operation (OEEC), precursor of the current Organization of the Economic Co-operation and Development (OECD), would lead the regime to negotiate their membership as a full-member. The agreement was achieved in 1955, and Spain entered the Agriculture and Food Commission of the OEEC, thus strengthening the ties established after the Civil War with their main importers of agricultural products, located in Western Europe
 Crespo, M. L. J. (2004). Spain in Europe, 1945-2000: From ostracism to modernity. Ed. Marcial Pons, Madrid.
 Gonzalez, A. (September 1st, 20122). An anguished hope. Spanish and Portuguese businessmen in face of the entry in the EEC, 1957-197. Hispania – Spanish Review on History, 72, 242, 699-722
 Zaratiegui, J. M. (2010). One Europe for two Spains: First steps towards integration, 1957-1963. Pamplona: Editions University of Navarra.
 Senante, B. H. C. (2006). Spain in face of the European integration: the first rapprochement. Valencia: Institució Alfons el Magnànim
 An average of 48% of Spanish exports went to the common market – the figures could reach 80% in some agricultural products-, while the 30% of imports came from the member countries. Nearly 41% of the foreign investments in Spain had the same origin by then.
 By 1975, 348 companies operated in Spanish territory. Having as reference the 300 biggest industrial companies of the country, the US investments took the foreign participation in several productive sectors, such as the chemical sector (25,39%), electrical material sector (29,47%), iron and steel industry (59,43%), mechanical constructions (24’87%) or oil (100%). Between 1960 and 1975, taking into account only the main investments in the social capital of companies from the regulated sectors, the United States were the main origin of investment in (41%), followed by Switzerland (17%) and Germany (10%). Álvaro, M. A., Bank of Spain. (2012). The US direct investment in Spain: a study from the business perspective (c. 1900-1975)
 Ibárruri, D. (1960). History of the Communist Party of Spain. París: Éditions Sociales.
 See the statement in http://www.recursosacademicos.net/web/2015/03/16/resolucion-del-movimiento-europeo-de-munich-78-06-1962-a-propuesta-de-los-delegados-espanoles/
 Communist Party of Spain. (1975). Manifesto-programme of the Communist Party of Spain. Le Cheratte: Levaux
 Communist Party of Spain. (1978). Ninth congress of the Communist Party of Spain: Reports, debates, proceedings and documents: Madrid, 19-23 April, 1978. Madrid: PCE
 Italy supports the political entry of Spain in the EEC, http://elpais.com/diario/1977/09/02/internacional/241999216_850215.html
 French CP demands a referéndum on the entry of Spain in the EEC, http://elpais.com/diario/1978/12/03/internacional/281487604_850215.html
 Communist campaign in France against the extensión of the EEC, http://elpais.com/diario/1978/07/25/internacional/270165608_850215.html
 Communist Party of Spain (1982). Elections programme of the Communist Party of Spain: approved by the Central Committee of PCE in its meeting of September 15-16, 1982. Madrid: PCE
 Political Document of 4th European Left Congress, held in Madrid in December, 2013. http://de.european-left.org/positions/congress-motions/documents-4th-el-congress/final-political-document-4th-el-congress
 Communist Party (1984). Resolutions from the Communist Unity Congress. Nuevo Rumbo, num 1.
 The European Economic Community: Treaty of Rome, Single European Act: Full text. (1987). Madrid:Ed. Civitas
 Arderiu, E. (1988) “The industry in face of the entry of Spain in the EEC”. Annals of the Royal Academy of Economic and Financial Sciences, vol XX, pp. 25-47
 Several authors (2014). Figuring out the European Union. S.l.: Seminar of Critical Economy TAIFA
 A strong increase (2740%) in Foreign Portfolio Investment in these periods has to be added.
 Note the lack of coincidence among some of the data for the same periods and indicators used here, due to the diversity of statistical sources used in the work quoted, which has been the basis of some of the calculations made: Bajo, O (1992). An empirical analysis of the macro-economic determinants of foreign direct investment in Spain, 1961-1989. Moneda y Crédito. Núm. 194, pp 107-146.
 Felipe González declares that the industrial restructuring "is a key issue for our updating” with Europe, http://elpais.com/diario/1983/12/03/espana/439254006_850215.html
 Binda, Verónica. (2005). Between the state and the multinationals: Spanish industrial Company in the years of the integration in the European Economic Community. University of Barcelona.
 Guerrero, D. (2006). The exploitation: labour and capital in Spain (1954-2001). Mataró: Editions of Cultural Intervention.
 Several authors (2014). Figuring out the European Union. S.l.: Seminar of Critical Economy TAIFA.
 Initiative of Communist and Workers' Parties in order to study and ellaborate on European issues and to coordinate their activity, created in October 2013 and composed by 29 European Communist and Workers' parties, not only from member countries of EU.
 Communist Party of the Peoples of Spain. (2014). For the working class and the peoples: no to TTIP, no to monopolies, no to EU. Statement from the Executive Committee of PCPE. http://www.pcpe.es/index.php/comite-central/item/2147483720-por-la-clase-obrera-y-los-pueblos-no-al-ttip-no-a-los-monopolios-no-a-la-ue. See also: Alfonso Reyes (December 2014) TTIP. Causes and consequences of a war declaration against the working people. UyL