FamilySearch.org has a FREE database titled " Minnesota Naturalization Records and Indexes, 1872-1962 ".  It includes 1,041 people born in Greece and 181 born in Turkey . This publication contains naturalization records from United States District and Circuit Courts for the state of Minnesota. The collections are from Record Group 21 Records of the District Courts of the United States and are from the National Archives Branch in Kansas City, Missouri. United States District Court First Division. Winona. Naturalizations, 1896-1924 First Division Administrative History Note NARA Second Division. Mankato. Declarations of intention, 1906-1940; Naturalizations, 1897-1944 Second Division Administrative History Note NARA Third Division. St. Paul. Declarations of intention, 1872-1955; Naturalizations, 1859-1954 Third Division Administrative History Note NARA Fourth Division. Minneapolis. Declarations of intention, 1906-1962 Fourth Division Administrative History Note NARA Sixth Di...

University of Minnesota, Immigration History Research Center : AHEPA , National Office, Records, 1923-1950 IHRC98, 63 linear ft. . Bound correspondence of the local chapters for the period of 1923-1950. Historical sketch on-line. Argoe, Kostis Tamias, Papers, 1930-1969 IHRC238, 3 linear ft. (8 boxes). Published and unpublished articles; one-act plays; records of Greek American cultural organizations in Chicago, Illinois.; scrapbooks; and correspondence and printed material related to the Cyprus issue. Description on-line. Callimachos, Demetrios P., Papers, 1876-1963 IHRC397, 20 linear ft. . Biographical information, correspondence, writings and speeches, resources, legal documents, memorabilia, collected ephemera, and photographs. Description on-line with historical sketch. Daughters of Penelope, Chapter 35-Antigone, Minneapolis, Records IHRC514, 8 linear ft. Greek Community Council of Marysville, California, Records IHRC815, 0.5 linear...

If you live in the United States, chances are that your local library has a subscription to HeritageQuest Online (maybe even allowing you access online from home).  From there you can search PERSI  (The Periodical Source Index) at the Allen County Public Library, Fort Wayne, IN.  You can print a form online and order a copy of any article listed in the PERSI Index. Here are the titles of articles pertinent to  Greek immigrants in Minnesota : Greek immigration to Mankato, c.1914-1916  Blue Earth County Historian. Mankato MN: Winter 2006 Holy Trinity Greek Cath. church, 1912-2000, Brow .  Trembita. Minneapolis MN: Jul 2000. Vol. 12 Iss. 3