Question: During what conflict was much of the economy of Spain put under worker control?

The Western Sahara War (Arabic: حرب الصحراء الغربية‎ ‎ , French: "Guerre du Sahara occidental" , Spanish: "Guerra del Sahara Occidental" ) was an armed struggle between the Sahrawi indigenous Polisario Front and Morocco between 1975 and 1991, being the most significant phase of the Western Sahara conflict.  The conflict erupted after the withdrawal of Spain from the Spanish Sahara in accordance with the Madrid Accords (signed under the pressure of the Green March), by which it transferred administrative control of the territory to Morocco and Mauritania, but not the sovereignty.  In late 1975, Moroccan government organized the Green March of some 350,000 Moroccan citizens, escorted by around 20,000 troops, who entered Western Sahara, trying to establish a Moroccan presence.  While at first met with just minor resistance by the POLISARIO, Morocco later engaged a long period of guerrilla warfare with the Sahrawi nationalists.  During the late 1970s, the Polisario Front, desiring to establish an independent state in the territory, attempted to fight both Mauritania and Morocco.  In 1979, Mauritania withdrew from the conflict after signing a peace treaty with the POLISARIO.  The war continued in low intensity throughout the 1980s, though Morocco made several attempts to take the upper hand in 1989–1991.  A cease-fire agreement was finally reached between the Polisario Front and Morocco in September 1991.  Some sources put the final death toll between 10,000 and 20,000 people. <SEP> The Spanish Revolution was a workers' social revolution that began during the outbreak of the Spanish Civil War in 1936 and resulted in the widespread implementation of anarchist and more broadly libertarian socialist organizational principles throughout various portions of the country for two to three years, primarily Catalonia, Aragon, Andalusia, and parts of the Valencian Community.  Much of the economy of Spain was put under worker control; in anarchist strongholds like Catalonia, the figure was as high as 75%, but lower in areas with heavy influence by the Communist Party of Spain.  Factories were run through worker committees, agrarian areas became collectivized and run as libertarian socialist communes. Even places like hotels, barber shops, and restaurants were collectivized and managed by their workers. <SEP> The Economy of Kosovo is a transition economy.  Kosovo was the poorest province of the former Yugoslavia with a modern economy only established after a series of federal development subsidies in 1960s and 1970s.  During the 1990s abolition of province's autonomous institutions followed by poor economic policies, international sanctions, little access to external trade and finance, and ethnic conflict severely damaged the already-weak economy.  Since the declaration of independence in 2008 Kosovo's economy has grown each year, with relatively low effects from the global financial crisis; while there are many weaknesses for its potential in the future, many of them related to its internationally disputed status, there are also potential strengths, including its very low level of government debt ( as most of historical debts are paid still by Serbia) and future liabilities and the strength of its banking system (despite remaining obstacles to using this for productive loans).  Kosovo remains one of the poorest areas of Europe, with as much as 45% of the population living below the official poverty line, and 17% being extremely poor according to the World Bank. <SEP> Gaston Leval (born Pierre Robert Piller October 20, 1895 – April 8, 1978) was an anarcho-syndicalist, combatant and historian of the Spanish Revolution.