Fukui, K.; Sone, T.; Yamagata, K.; Otsuki, Y.; Sawada, Y.; Vetrova, V.; Vyatkina, M. (2008). "Relationships between permafrost distribution and surface organic layers near Esso, central Kamchatka, Russian Far East". Permafrost and Periglacial Processes. 19 (1): 85–92. doi:10.1002/ppp.606. S2CID130100766.
Fukui, K.; Sone, T.; Yamagata, K.; Otsuki, Y.; Sawada, Y.; Vetrova, V.; Vyatkina, M. (2008). "Relationships between permafrost distribution and surface organic layers near Esso, central Kamchatka, Russian Far East". Permafrost and Periglacial Processes. 19 (1): 85–92. doi:10.1002/ppp.606. S2CID130100766.