Perhaps you should try some spelling variations:
te sach » toc sach
xang ma » tang ma, sang ma, rang ma
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((xang ma) OR (nang ma)) hoi. hieu ve cac duc ((va dinh) or (may tinh)) viec cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((xang ma) OR (nang ma)) hoi. hieu ve cac duc ((va dinh) OR (may tinh)) viec cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((xang ma) OR (nang ma)) hoi. hieu ve cac duc ((va dinh) or (may tinh)) viec cua tre*".