Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
hieu va » lieu va, hieu qua
lam loc » lam duoc, lam ngoc
va danh » va dinh, va hanh, dia danh
va dan » ca dan, va dao, va dau
di cau » da cau, diem cau
va lam » van lam, va lap

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y ((nang ma) or (tang ma)) hoi. hieu va lam loc ((va danh) or (va dan)) di cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang ma) OR (tang ma)) hoi. hieu va lam loc ((va danh) OR (va dan)) di cau tren.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((nang ma) or (tang ma)) hoi. hieu va lam loc ((va danh) or (va dan)) di cau tren*.