Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang cho » nang chon, ngang cho, nang cao
van hanh » van thanh, ban hanh, van anh
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
cho hoc » co hoc, khoa hoc
hieu ve » hieu van
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
cua cau » cua chu, cua cay, cua can

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach tu nang cho hoc. ((hieu ve) or (hieu va)) cac duc van hanh vi ((cua cau) OR (cua cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu nang cho hoc. ((hieu ve) OR (hieu va)) cac duc van hanh vi ((cua cau) OR (cua cac))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu nang cho hoc. ((hieu ve) or (hieu va)) cac duc van hanh vi ((cua cau) OR (cua cac))*".