Perhaps you should try some spelling variations:
dong khoan » dong khoa, dung khoa, dong hoa
khoan hoi » khoan nhoi, khoa hoi, khoa hoc
cham cuu » cap cuu, chat cua
cuu ban » cuu van, cua ban, cuu san
tinh va » tich va, trinh van, trinh vat
tinh vi » trinh vi, tinh voi, dinh vi
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
y dong » ly dong, ty dong, _ dong

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 dong khoan hoi. ((hieu ve) or (lieu va)) cham cuu ban ((tinh vi) OR (tinh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y dong khoan hoi. ((hieu ve) OR (lieu va)) cham cuu ban ((tinh vi) OR (tinh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y dong khoan hoi. ((hieu ve) or (lieu va)) cham cuu ban ((tinh vi) OR (tinh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y dong khoan hoi. ((hieu ve) or (lieu va)) cham cuu ban ((tinh vi) OR (tinh va)) cua tre*.