Good expression references?

Does anyone have any tips on where I can find good reference pictures? I’m working my way through the human body on anatomy and am currently stuck with expressions, specifically with mouths.
I can handle the eyes and eyebrow, but the mouths always looks so out of place. I also find it hard finding natural looking references? Like I tried to get the hang of laughing expression and I felt like every picture I found was so stock-y and fake? Same with shouting.

Any tips and tricks is greatly appreciated!