Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cua triet, dua tren
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
ve chat » va chat, van chat
tu nang » tru nang, tu nong, tu nano
cuu tre » cau tren, cau treo
ve tai » te tai, de tai, le tai

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 tu nang cau hoi. hieu ((ve tai) or (ve chat)) ly va danh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nang cau hoi. hieu ((ve tai) OR (ve chat)) ly va danh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nang cau hoi. hieu ((ve tai) or (ve chat)) ly va danh va ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nang cau hoi. hieu ((ve tai) or (ve chat)) ly va danh va ((cua tre) OR (cuu tre))*.