NOTE: all the information comes form wikipedia, starting in Independence Referendum page
YEAR NATION QUESTION
1846 Liberia Declaration of Independence
1853 Maryland ??
1905 Norwegian whether you approve the “already completed dissolution of the union”
1933 West Australia Question 1: Are you in favour of the State of Western Australia withdrawing from the Federal Commonwealth established under the Commonwealth of Australia Constitution Act (Imperial)?
Question 2: Are you in favour of a Convention of Representatives of equal number from each of the Australian states being summoned for the purpose of proposing such alterations in the Constitution of the Commonwealth as may appear to such Convention to be necessary?
1944 Iceland Voters were asked whether the Union with Denmark should be abolished and whether to adopt a new republican constitution
1946 Faroe Islands ??
1945 Cambodia It was a six-issies referendum: The questions included whether the country should become independent, and whether the presence of foreign military forces should be refused.
1958 Guinea Do you approve the Constitution proposed by the Government of the Republic?
1961 Western Samoa Do you agree that on 1 January 1962 Western Samoa should become an independent State on the basis of that Constitution?
1962 Algeria Do you want Algeria to become an independent state, co-operating with France under the conditions defined in the declarations of 19 March 1962
1964 Malta Do you approve of the constitution proposed by the Government of Malta, endorsed by the Legislative Assembly, and published in the Malta Gazette?
1964 Southern Rhodesia Are you in favour of or against Southern Rhodesia obtaining independence on the basis of the 1961 Constitution of Southern Rhodesia
1970 Bahrain ??
1977 Djibouti ?? Bailout: Independence | Remain a territory in the French Republic
1983 Federated States of Micronesia Question 1) Do you approve of the Compact of Free Association and its related Agreements?
Question 2) If the Compact of Free Association is not approved, I recommend to the government that it negotiate an agreement with the government of the United States consistent with my preference for the following political status:[ ] Independence | [ ] A relationship with the United States other than Free Association. You may describe that status
1990 Slovenia Should the Republic of Slovenia become an independent and sovereign state?
1991 Armenia
1991 Azerbaijan
1991 Croatia Question (1) proposing independence of Croatia (93.24% in favor, 4.15% against).
1991 Estonia Question (2), proposing that Croatia should remain in Yugoslavia (5.38% in favor, 92.18% against).
1991 Georgia (country) Do you support the restoration of the independence of Georgia in accordance with the Act of Declaration of Independence of Georgia of May 26, 1918?
1991 Latvia are you in favour of a democratic and independent Republic of Latvia
1991 Lithuania
1991 Republic of Macedonia
1991 Nagorno-Karabakh
1991 Ukraine Do you support the Act of Declaration of Independence of Ukraine
1991 Transnistria
1991 Turkmenistan Do you agree with the legislative establishment of Turkmenistan as an independent democratic state? Do you support the statement of the President and Supreme Soviet of the Turkmenistan Soviet Socialist Republic “On the domestic and foreign policy of Turkmenistan” and the practical activity to implement it?
1991 Uzbekistan
1992 Bosnia and Herzegovina Are you in favor of a sovereign and independent Bosnia-Herzegovina, a state of equal citizens and nations of Muslims, Serbs, Croats and others who live in it?
1992 South Ossetia
1993 Eritrea
1994 Moldova Do you want the Republic of Moldova to develop as an independent and unitary state, in the frontiers recognized in the day where Moldova declared sovereignty, to promote a policy of neutrality and to maintain mutually-benefiting economic relations with all the countries of the world, and to guarantee its citizens equal rights, according to international law?
1995 Bermuda Are you in favour of independence for Bermuda?
1999 East Timor Do you accept the proposed special autonomy for East Timor within the unitary state of the Republic of Indonesia?Do you accept the proposed special autonomy for East Timor within the unitary state of the Republic of Indonesia?
Do you reject the proposed special autonomy for East Timor, leading to East Timor’s separation from Indonesia?
2005 Iraqi Kurdistan
2006 Montenegro Do you want the Republic of Montenegro to be an independent state with a full international and legal personality?
2006 South Ossetia should South Ossetia preserve its present status of a de facto independent state?
2006 Transnistria 1) Renouncing independence and potential future integration into Moldova. 2) Independence and potential future integration into Russia
2009 Tamil Eelam
2011 South Sudan  Voting form used in the referendum.
2014 Scotland Should Scotland be an independent country?
QUESTIONS NOT FOUND (Please comment this entry if you know them)
1853 Maryland
1946 Faroe Islands
1970 Bahrain
1991 Armenia
1991 Azerbaijan
1991 Lithuania
1991 Republic of Macedonia
1991 Nagorno-Karabakh
1991 Transnistria
1991 Uzbekistan
1992 South Ossetia
1993 Eritrea
2005 Iraqi Kurdistan
2009 Tamil Eelam
lalala lalalala * * *

Expected referendums:

Late 2013 Anguilla Anguillan independence referendum
18/09/14 Scotland Scottish independence referendum.
2014 Catalonia Catalonian independence referendum.
Between 2014 and 2019 New Caledonia New Caledonian independence referendum (envisioned by Nouméa Accord, 1998).
Between 2015-2020 Autonomous Region of Bougainville Bougainville independence referendum (envisioned by Peace Agreement, 2000)