Note that some South Vietnamese provinces (post-1975) were merged together and were wiped off the map/dissolved, while many others retained their name of Southern origin and continued to exist. A few provinces were also split to make way for new, smaller provinces.
Make sure to use "," to separate the names of the provinces if there are more than one mentioned in that box
If the old province is mentioned more than 1 time, then it is most likely split or merged (e.g: Hậu Nghĩa which is mentioned 4 times)