Perhaps you should try some spelling variations:
khoan hoi » khoan nhoi, khoa hoc, khoa doi
ban tinh » ban thanh, quan tinh, ban hanh
khoa hoi » khoa hoc, khoa doi, khoa noi
cham cuu » cap cuu, chat cua
tu sach » thu sach, su sach, te sach
tinh vi » trinh vi, tinh voi, tinh va
cuu ban » cuu van, cua ban, cuu san
cua tre » cua te, cuu tre, cua triet
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
ly dong » ly dung, lao dong, huy dong
vi cua » vai cua, di cua

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