Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Haas. 1986. What is nationalism and why should we study it?. International Organization (Summer).
Geertz (1963) takes a primordial view of ethnicity. Compare to Haas's instrumental view. Lijphart (1995) criticizes both approaches in "Multiethnic Democracy."
Research on similar subjects