Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
thien van » thi van
va thanh » gia thanh, ban thanh, va tinh
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, lieu va, hieu ve
va hanh » van hanh, va danh, ban hanh
cu tren » tu tren, dua tren
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho
va cu » va cau, va chu, va su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach y nang x hoi. ((hieu van) or (thien van)) cham thuc ((va hanh) OR (va thanh)) va cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y nang x hoi. ((hieu van) OR (thien van)) cham thuc ((va hanh) OR (va thanh)) va cu tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach y nang x hoi. ((hieu van) or (thien van)) cham thuc ((va hanh) OR (va thanh)) va cu tren*".