Antonym for "deficient"

Solution 1:

You could say it is replete with sources:

replete adjective [ predic. ]
filled or well-supplied with something: sensational popular fiction, replete with adultery and sudden death.

Solution 2:

Sufficient, without doubt!

1. Equal to the end proposed; adequate to wants; enough; ample; competent; as,
2. Possessing adequate talents or accomplishments; of competent power or ability; qualified; fit.

Solution 3:

The dissertation has a surfeit of sources.

The dissertation is over-endowed with sources.

But only if you consider a surplus to be the opposite of a shortage.