Comment on “A new mathematical approach for finding the solitary waves in dusty plasma” [Phys. Plasmas 5, 3918 (1998)]

It is argued that in their recent paper Das and Sarma use a method derived by Malfliet without mentioning his work. Quite to the contrary, they claim to have developed the method themselves (some 5 years later) with their co-workers. Moreover, Das and Sarma use expansions without checking their validity and applicability, show little insight into the theory of integrable or nonintegrable evolution equations and claim to be among the pioneers in dusty plasma research whereas they came late to the field.