Perhaps you should try some spelling variations:
nam thuc » nam thuoc, nam thu, nam tu
vanh dai » van dai, vanh tai, lanh dao
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va vanh » va van, va danh, va hanh
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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