Perhaps you should try some spelling variations:
xang cao » nang cao, lang cao, quang cao
tu sach » thu sach, su sach, te sach
cac duc » cac du, cao duc, cac dac
doan vi » doan va, don vi, doan thi
sach tu » sach thu, cach tu, sach ty
cua tuc » cua duc, cua tu, cua thuoc
hieu ve » hieu va, hieu van
cao hoa » cao hoat, cao khoa, cau hoa
tu xang » ty xang, tu lang, tu quang
ve cac » va cac, vien cac
dan vi » don vi, dan va, gan vi
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 tu xang cao hoa. hieu ve cac duc va ((dan vi) OR (doan vi)) ((cua te) or (cua tuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu xang cao hoa. hieu ve cac duc va ((dan vi) OR (doan vi)) ((cua te) OR (cua tuc))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu xang cao hoa. hieu ve cac duc va ((dan vi) OR (doan vi)) ((cua te) or (cua tuc))*".