Declaration of Independence of the Republic of Crimea

The Declaration of Independence of the Autonomous Republic of Crimea and Sevastopol was a joint resolution adopted on March 11, 2014 by the dissolved Supreme Council of Crimea and the Sevastopol City Council that proclaimed the Autonomous Republic of Crimea and the city of Sevastopol a sovereign state — the Republic of Crimea. The decision was based on the results of an referendum that was held on March 16, 2014 after Russian troops took over Crimea and seized the region's parliament. The declaration of independence and the referendum following it was not internationally recognised by most countries.
According to the Declaration, the newly formed state has the right to apply to Russia for the inclusion of the territory in the federation as a separate subject. 
In Ukraine's constitution, the Autonomous Republic of Crimea and the city of Sevastopol are recognised as integral parts of Ukraine, and changes to the territory of Ukraine is possible only after the relevant result of an All-Ukrainian referendum. 
Translated copy.
The document reads as follows:
International reaction.
Russia recognised the Republic of Crimea's declaration of independence and agreed to incorporate the Republic into the Russian Federation following a referendum. However, the referendum was condemned as "illegal" by the European Union and countries such as the United States. US President Barack Obama said that Russian actions were a violation of Ukrainian sovereignty and that the referendum would "violate the Ukrainian constitution and international law". On 27 March 2014, the United Nations General Assembly adopted the "Territorial Integrity of Ukraine" Resolution, which recognised Crimea as part of Ukraine.