Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
cao suc » cao su, cao duc
cac duc » cac du, cao duc, cac dac
sach ty » sach y, sach tu, sach thu
cua chu » sua chua
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
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: toc sach ty ((nang xa) or (nang x)) hoi. hieu ve ((cac duc) or (cao suc)) van hanh vi cua chu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty ((nang xa) OR (nang x)) hoi. hieu ve ((cac duc) OR (cao suc)) van hanh vi cua chu.
• Adding a wildcard symbol may retrieve word variants: toc sach ty ((nang xa) or (nang x)) hoi. hieu ve ((cac duc) or (cao suc)) van hanh vi cua chu*.