:about or concerning (something or someone):in relation to关于
I have something further to add with reference to [=with respect to, in regard to] what was said earlier.关于我先前说过的话,我想再补充一些。
I am writing in reference to your recent letter.我这封信是对您最近来信的回复。
The course covers ancient history with special reference to the Roman Empire. [=the course is about ancient history and especially about the Roman Empire]这门课程讲述古代史,特别是罗马帝国史。