STATIONARY WAVES IN NON-LINEAR, PERIODICALLY MODULATED MEDIA WITH HIGHER GROUP DECELERATION СтатьяVOLOSHCHENKO Y.I., RYZHOV Y.N., SOTIN V.E.ЖУРНАЛ ТЕХНИЧЕСКОЙ ФИЗИКИ. Том 51. 1981. С. 902-907
ON THE CRITERIA OF OBSERVATION OF THE GRAVITATIONAL LENS EFFECT СтатьяMITSKIEVIC N.V.ASTRONOMICHESKII ZHURNAL. Том 57. 1980. С. 1339-1340