Finding Verb Roots

I am currently modifying my Flashworks database and adding the roots for the verbs to the flashcard, which I like to memorize along with the word and its definition. I can find the roots for the verbs which occur more than 50 times in the N.T. in the textbook, but I'd like the roots for all the verbs in the database - at least for the ones down to 30 occurrences. Where can these be found? Thanks.