primary sources
news sources
energy sources
sources of income
reliable sources
A: Where are your sources for this report?
A：你这份报告的来源在哪里？
B: I used several reliable online sources.
B：我使用了几个可靠的在线来源。
1) 来源，起源
2) 消息来源
3) 资源
1. 来源，出处
noun
1. The place, person, or thing from which something originates or can be obtained.
Synonym: origins, roots, foundations