Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
ve cam » ve cac, va cam, ve cai
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va cua » va chua, via cua, ca cua
lo va » lo van, lao va, ly va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang cau hoi. hieu ((ve cam) or (ve cham)) lo va dan va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang cau hoi. hieu ((ve cam) OR (ve cham)) lo va dan va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang cau hoi. hieu ((ve cam) or (ve cham)) lo va dan va cua tre*.