Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
sach ky » sac ky, sach ty, sach kem
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
cua tre » cua te, cuu tre, cua triet
lo van » le van, vo van, so van
vi cua » vai cua, di cua
lo va » lao va, ly va, le va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach ky) or (sach y)) nang cau hoi. hieu vu cham ((lo va) OR (lo van)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sach y)) nang cau hoi. hieu vu cham ((lo va) OR (lo van)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ky) or (sach y)) nang cau hoi. hieu vu cham ((lo va) OR (lo van)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ky) or (sach y)) nang cau hoi. hieu vu cham ((lo va) OR (lo van)) hanh vi cua tre*.