Research
How many sources should you consider?
Normally, the longer the paper the more in-depth the treatment of the topic will be. Depth and thoroughness typically require more resources; and the more resources you require, the more time you will need to devote to finding them.
The number of resources suitable for research papers varies among disciplines. In the absence of specific directions, a common guideline is to have 5-8 resources for a shorter paper and 8-10 resources for a longer paper.