How to call Father's cousin in Cantonese

Question

How to call my Father's Cousin in Cantonese? But this Cousin is my Grandmother's sistor's son? The answer better has some document prove it.

Can I found the answer in Chinese Dictionary or any document? my Grandma need some prove.because she said it should be 表舅父. Of couse, I knew it is wrong.

Answer 1

媽媽的表兄弟才叫表舅父，爸爸的表哥是表伯父，爸爸的表弟是表叔。

Answer 2

表伯父 if older than your father
表叔 if younger

Answer 3

表哥或表弟