Create a section within your mini sketchbook about Post Impressionism. (Post = after)
Include the same content as before:
Key facts and information such as the ideas behind the movement, where it took place and the key artists involved
Your own response (drawing/painting etc)
Printed images but only if possible
It is completely up to you how to you present this in your book. Be as creative as you like. I have used a fairly simple but clear presentation layout in my example.