Synonyms for Sources:

n.

•beginnings (noun)
inceptions, derivations, dawns, commencements, creations, nativities, cradles, inaugurations, starts, introductions, Embryos, preparations, springs, Births, infancies, origins, beginnings, precursors, stems, conceptions, preludes, sprouts.
•causes (noun)
inspirations, Drives, motives, motivators, grounds, compulsions, actions, executions, causes, evocations, roots, forces, Bases, factors, Stimuli, mainsprings.

Usage examples for sources

1. From what sources does the money come for road repair in your county? – Community Civics and Rural Life by Arthur W. Dunn