You should make your own notes by going through past papers and syllabus in hand for each subject. However, if you really do want ready made notes you could go to CSS preparation academies (NOA, KIPS) and simply buy the books/notes of almost all subjects from their stationary shops (Even without getting admission). Beware though, they cost atleast 800 per book and can easily go higher to a price of 1500 per book.

Most people refer dogar or other publisher's book but those are either replete with errors or simply copy pasted from google Wikipedia etc. Most if not all dont expansively cover the syllabus properly and leave out entire sections

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