What is another word for reference?

The best substitute for "reference" depends on the context. Here are some options:

For citing sources:

* Citation

* Source

* Bibliography

* Footnote

* Endnote

For general meaning of "referring to something":

* Mention

* Allusion

* Quotation

* Indication

* Pointer

* Clue

* Hint

For the act of consulting something:

* Consult

* Review

* Examine

* Check

For a person who provides information about someone's character:

* Recommendation

* Endorsement

* Testimonial

For a person who is being referred to:

* Referral

* Contact

* Lead

Please provide more context for your question, and I can give you a more specific answer.