union with Serbia, which is today mentioned in the preamble of the Constitution of Croatia. See also Austro-Slavism Czechoslovakia–Yugoslavia relations Ethnic federalism State of Slovenes, Croats and Serbs Triune Kingdom Union of Hungary and Romania References Further reading Bartulin, Nevenko. "From Independence to Trialism: The Croatian Party of Right and the Project for a Liberal “Greater Croatia” within the Habsburg Empire, 1861–1914." in by Matthew P. Fitzpatrick, ed. Liberal Imperialism in Europe (Palgrave Macmillan, 2012) pp. 115-140. Kann, Robert A. The multinational empire: nationalism and national reform in the Habsburg monarchy, 1848-1918. (Columbia University Press, 1950). Miller, Nicholas J. "RW Seton-Watson and Serbia during the Reemergence of Yugoslavism, 1903–1914." Canadian Review of Studies in Nationalism 15 (1988): 59-69. online Sources Federalism in Austria-Hungary Politics of Austria-Hungary South Slavic history 19th century in Croatia 20th century in Croatia