Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang cho » nang chon, ngang cho, nang cao
chat vuc » chat xuc, chat huu, chat cua
van hanh » van thanh, ban hanh, van anh
cho hoc » co hoc, khoa hoc
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: ((te sach) OR (toc sach)) ky nang cho hoc. hieu ve ((chat vuc) or (chat va)) van hanh vi cua cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang cho hoc. hieu ve ((chat vuc) OR (chat va)) van hanh vi cua cac*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang cho hoc. hieu ve ((chat vuc) or (chat va)) van hanh vi cua cac*".