eh...why do you want to buy h3 notes? if ure taking it, wont
your school provide you with it?
for maths u can always go library borrow/go bookstores to buy
the h3 textbooks. for maths u can find the "introduction to graph
theory, h3 mathematics" by tay eng guan, "principles and techniques
in combinatorics" by koh khee meng and "differential equations:
models and methods" by ang keng cheng. those authors created the
book with reference to the h3 math syllabus. i think more useful in
general than school given notes....