Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
chua tre » chua tri, cua tre, chua trieu
nang ma » tang ma, sang ma, nang cao
sach lo » sach dao, sach doi, sach hoi
cac tac » cac toc, cac dac, cac tai
cac bac » cac bai, cac ban, cac cach
va hang » van hang, va nang, va lang
va chua » vua chua, ca chua, va chu
tu sach » thu sach, su sach, te sach

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 lo ((nang ma) or (mang may)) hoa. hieu viec ((cac tac) OR (cac bac)) va hang va chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach lo ((nang ma) OR (mang may)) hoa. hieu viec ((cac tac) OR (cac bac)) va hang va chua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach lo ((nang ma) or (mang may)) hoa. hieu viec ((cac tac) OR (cac bac)) va hang va chua tre*".