Perhaps you should try some spelling variations:
manh thanh » danh thanh, minh thanh, manh thang
thanh lai » thanh hai, thanh lap, thanh loi
duc manh » suc manh, duc anh, duc minh
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, hai cua, lai chau
nam duc » nam duoc, pham duc, nam thuc
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach thu, xach tay
long ha » dong ha, cong ha, dong hoa
lang xa » lang ha, dang xay, lang van
sach tu » sach thu, cach tu, sach uu

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