How do you know if you have enough sources?

[NYC_SKP]

1. This depends on your audience, I suppose.

If it's for a post-graduate program, your adviser would know.

If it's for a different academic purpose, you might be able to compare your work to similar presentations and identify a range, especially if you can check a similarly obscure topic.

Personally, the quality and variety of sources means more to me than the quantity.

If you feel the need to augment your traditional published sources with blogs and/or sermons, you might be able to identify those with the greatest circulation or that are most representative.

Wish I could help more.