How can I compile a study material of a course in this case?
I suppose you are obliged to prepare what some may recall as a minimum learning material. It is what a student might need to get the a broad knowledge of the subject before s/he is to delve into the details.

If you are concerned that the original source ought to be referred due to its importance, then you might include this sentence...


  The provided study material is by no means a complete replacement to the prescribed textbooks/sources on the subject. 


...somewhere in the beginning of the material, such as the preface section. It what I usually do when compiling such notes.