In 1905 he left for Berdiansk in Southern Russia. There he resumed publication of the journal "Vardar" and worked as Bulgarian teacher. In many of his next articles after 1905 Misirkov exposed pro-Bulgarian views and even categorically renounced the point of his book "The Macedonian matters". On 18 April 1907 Misirkov began to cooperate with the issued in Sofia magazine "Macedonian-Adrianople Review", edited by Nikola Naumov, which was "de facto" organ of the IMARO. On 24 April 1909 K. Missirkov printed in Odessa in a separate booklet his work "South Slavic epic legends of the marriage of King Volkashin in connection with the question of the reasons for the popularity of Krali Marko among the South Slavs". On 1 October 1909 he printed the article, "The foundations of a Serbian-Bulgarian rapprochement" in the Magazine "Bulgarian collection" edited by Bulgarian diplomats in St. Petersburg. By the time, a Slavic Festival was held in Sofia in 1910 and Missirkov was attend as its guest of honor. In 1910–1911, he translated from Bulgarian to Russian the book of the Bulgarian geographer Prof. Atanas Ishirkov "Bulgaria".