Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
van cach » va cach, van canh, vat cach
doanh va » doan va, doanh tai, doanh cua
doanh vi » doan vi, doanh vien, doanh tai
thuc ban » thuoc ban, thuc dan, thu ban
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
nang ma » tang ma, sang ma, nang cao
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: so sach y ((lang xa) or (nang ma)) hoi. hieu van cach thuc ban ((doanh vi) OR (doanh va)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((lang xa) OR (nang ma)) hoi. hieu van cach thuc ban ((doanh vi) OR (doanh va)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((lang xa) or (nang ma)) hoi. hieu van cach thuc ban ((doanh vi) OR (doanh va)) cua te".
• Adding a wildcard symbol may retrieve word variants: so sach y ((lang xa) or (nang ma)) hoi. hieu van cach thuc ban ((doanh vi) OR (doanh va)) cua te*.