Visas must be obtained from a Turkish Consulate, generally
the one nearest your place of residence. You must take your "Invitation
Letter" from Dicle University and apply to the Turkish Consulate with
the other required documents.
Please note that it may take up to 8 weeks to get the visa.
You may find Consulate information through the Turkish Ministry of Foreign
Affairs website: http://www.mfa.gov.tr