You can look at Jiuchenggong, in which a large number of strokes have the meaning of running script, especially some short strokes. Although there is no connection between strokes, as long as you look carefully, you will find that there is a connection between strokes (even a little inadvertently) and the breath is smooth. With a certain foundation, you can write faster (step by step) and experience the connection of that kind of breath.
If you think you are skilled enough, look at the running script of Wang Xizhi and Mi Fei.