Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van nang » van quang, van ban, van dong
hanh ki » hanh vi, hanh ky, hanh kien
qua ban » cua ban, qua quan
tu sach » thu sach, su sach, tu cach
hieu ve » hieu va, hieu van
te sach » toc sach
ve cac » va cac, vien cac
ki su » ky su

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) OR (te sach)) van nang x ho. hieu ve cac ((duc tan) or (qua ban)) hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) van nang x ho. hieu ve cac ((duc tan) OR (qua ban)) hanh ki su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) van nang x ho. hieu ve cac ((duc tan) or (qua ban)) hanh ki su triet*".