HOLMIUM TRIIODIDE INTERACTION WITH ALKALI-METAL IODIDE Article MOLODKIN A.K., KARAGODINA A.M., NECHITAILOV S.B., DUDAREVA A.G., KROKHINA A.G. ZHURNAL NEORGANICHESKOI KHIMII / Russian Journal of Inorganic Chemistry. Федеральное государственное бюджетное учреждение "Российская академия наук". Vol. 31. 1986. P. 789-793
A VARIATIONAL PRINCIPLE FOR HYPOELLIPTIC EQUATIONS WITH CONSTANT-COEFFICIENTS Article FILIPPOV V.M. Differential Equations. Vol. 22. 1986. P. 258-262