There are several synonyms for the phrase "abundant sources", which refers to a plentiful amount of resources or information available. One alternative could be "ample supplies", which connotes a large or generous quantity of something. Another option could be "copious reservoirs", which implies an extensive reserve of resources. "Rich stores" is another possible synonym, indicating that there is an abundant amount of something valuable or useful. "Full wells" is a more poetic way of expressing the same idea, while "bountiful founts" suggests a generous and overflowing source of information or resources. Ultimately, there are many ways to describe a vast and abundant collection of sources.