Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
va doanh » van doanh, vay doanh, va danh
cham tuc » pham thuc, tham thuc, cham soc
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cuc tre » duc tre, cua tre, cuu tre

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 y ((nang xa) or (nang ma)) hoi. hieu ve ((cham tuc) OR (nham thuc)) va doanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (nang ma)) hoi. hieu ve ((cham tuc) OR (nham thuc)) va doanh tai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) or (nang ma)) hoi. hieu ve ((cham tuc) OR (nham thuc)) va doanh tai cuc tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (nang ma)) hoi. hieu ve ((cham tuc) OR (nham thuc)) va doanh tai cuc tre*.