Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cac truc » cau truc, cac tru, cac trung
hieu cua » hieu qua, dieu cua, bieu cua
vien cac » vien bach, vien dai, vien da
sach tu » sach thu, cach tu, sach ty
dang xa » dang xay, lang xa, dang ha
va hanh » van hanh, va thanh, ban hanh
va dinh » van dinh, va kinh, va tinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach tu ((dang xa) or (dung va)) hoi. hieu cua cac truc ((va hanh) or (va dinh)) vien cac tro~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach tu ((dang xa) OR (dung va)) hoi. hieu cua cac truc ((va hanh) OR (va dinh)) vien cac tro.
• Adding a wildcard symbol may retrieve word variants: thuoc sach tu ((dang xa) or (dung va)) hoi. hieu cua cac truc ((va hanh) or (va dinh)) vien cac tro*.