Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thi nang » thi cong, ki nang, thi hanh
van hanh » van thanh, ban hanh, van ban
vai cua » dai cua, hai cua, lai cua
van anh » van thanh, tuan anh, van minh
cua cau » cua cac, cua chu, cua cay
cac ung » cac chung, cac cong, cac dang
hieu ve » hieu va, hieu van
nang co » nang cao, nang doc, nang noi
ve cac » va cac, vien cac

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)) thi nang co hoc. hieu ve cac ung ((van hanh) or (van anh)) vai cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) thi nang co hoc. hieu ve cac ung ((van hanh) OR (van anh)) vai cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) thi nang co hoc. hieu ve cac ung ((van hanh) or (van anh)) vai cua cau*".