SanDic
Sanskrit-English Dictionary
...Apte's The practical Sanskrit-English dictionary. Poona: Prasad Prakashan, 1957-1959. 3v.
Arthur Anthony Macdonell
A practical Sanskrit dictionary with transliteration, accentuation, and etymological analysis throughout. London: Oxford University Press, 1929.
Maṇḍala Pati dāsa
List of verbal roots with final forms
http://sourceforge.net/p/dhatu-patha
Monier Williams
Sanskrit-English Dictionary