Perhaps you should try some spelling variations:
thien van » thi van
thanh vi » thanh va, thanh ve, nhanh vi
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
nam ma » nam mua, nam a, nam va
ma van » mai van, va van, ha van

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 xa) or (nang ma)) hoi. thien van nam ma van ((thanh vi) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. thien van nam ma van ((thanh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (nang ma)) hoi. thien van nam ma van ((thanh vi) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. thien van nam ma van ((thanh vi) OR (hanh vi)) cua tre*.