Forces of Sardinia) and the German Karl Hans Lungerhausen, general of the 90th Panzergrenadier Division. Post-Second World War period In 1946, by popular referendum, Italy became a republic, with Sardinia being administered since 1948 by a special statute of autonomy. By 1951, malaria was successfully eliminated by the ERLAAS, Anti-malaric Regional Authority, and the support of the Rockefeller Foundation, which facilitated the commencement of the Sardinian tourist boom. With the increase in tourism, coal decreased in importance but Sardinia followed the Italian economic miracle. In the early 1960s, an industrialisation effort was commenced, the so-called Piani di Rinascita (rebirth plans), with the initiation of major infrastructure projects on the island. These included the construction of new dams and roads, reforestation, agricultural zones on reclaimed marshland, and large industrial complexes (primarily oil refineries and related petrochemical operations). With the creation of petrochemical industries, thousands of ex-farmers became industrial workers. The 1973 oil crisis caused the termination of employment for thousands of workers employed in the petrochemical industries, which aggravated the emigration already present in the 1950s and 1960s. Sardinia faced the creation of military bases on the island, like Decimomannu Air Base and Salto di Quirra (the biggest scientific military base in Europe) in the same decades. Even now, around 60% of all Italian and NATO military installations in Italy are on Sardinia, whose area is less than one-tenth of all the Italian territory and whose population is little more than the 2.5%; furthermore, they comprise over 35,000 hectares used for experimental weapons testing, where 80% of the military explosives in Italy are used. Sardinian nationalism and local protest movements became stronger in the 1970s, and a number of bandits (anonima sarda) started a long series of kidnappings, which ended only in the 1990s. This also gave rise to various militant groups that blended separatist and communist ideas, the most famous being Barbagia Rossa and the Sardinian Armed Movement, which perpetrated several bombings and terrorist actions between the 1970s and the 1980s. In the span of just two years (1987–1988), 224 bombing attacks were reported. In 1983 a prominent activist of a separatist party, the Sardinian Action Party (Partidu Sardu – Partito Sardo d'Azione), was elected president of the regional parliament, and in the 1980s several other movements calling for independence from Italy were born; in the 1990s some of them became political parties, even if in a rather disjointed manner.