Speaking of and With reference to

With reference to and speaking of are semantically related in with regard to topic. In some cases you can use "With reference to" instead the word "Speaking of" as an adverb or a preposition, when it comes to topics like in connection with.

Speaking of and with reference to are semantically related in with regard to topic. You can use "Speaking of" instead the phrase "With reference to" as an adverb or a preposition, if it concerns topics such as in connection with.