Refer to the Users' Guide if you have any problems. ✬

Mary didn't refer to the accident she had seen. ✬

Which dictionary did you refer to? ✬

What does it refer to? ✬

Don't refer to this matter again, please. ✬

Please refer to page ten. ✬

Please refer to paragraph ten. ✬

I often refer to the dictionary. ✬

Refer to the instruction manual if you need to fix the refrigerator. ✬

Nowadays, we often use the term "senior citizen" to refer to old people. ✬