Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
assist [əˈsɪst] vt помога́ть (помо́чь*perf) +dat ; (financially) соде́йствовать (impf/perf) +dat
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.