The 4th volume of the largest Russian-Crimean Tatar dictionary has been published. This volume completed the many years of work of the Crimean teacher, linguist and lexicographer Seyran Useinov. During his lifetime he managed to publish only 2 volumes. The 3rd volume was published by his son Dilyaver Useinov. And the 4th has been published by his grandson Kemal Useinov. The final volume included about 30 thousand words from the letter “П” («P2») to the letter “Я” («Ya»).