In “A Russian-Yakut-Ewenki Trilingual Dictionary” by N.V. Sljunin, José Andrés Alonso de la Fuente offers the philological edition of a very early twentieth-century source of two indigenous languages from Siberia. This edition includes the facsimile of the original handwritten document.Whereas specialists have known about the existence of Sljunin’s Yakut data by indirect references to it in at least one standard dictionary, there was no available information regarding Sljunin’s Ewenki data. Furthermore, careful linguistic analysis reveals that the Ewenki variety reflected in Sljunin’s dictionary may have already dissapeared.