Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
lang dai » lang hai, lang mai, lang chai
hanh ki » hanh vi, hanh ky, hanh kien
xuc van » duc van, luc van, vuc van
va cham » va chat, va tham
tu sach » thu sach, su sach, tu cach
dai hoi » dai hoc, dai hai, dai moi
uu lang » cu lang, tu lang, xu lang
te sach » toc sach
va cao » va cac, va co, va dao
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)) uu lang dai hoi. hieu ((va cao) or (va cham)) xuc van hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) uu lang dai hoi. hieu ((va cao) OR (va cham)) xuc van hanh ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) uu lang dai hoi. hieu ((va cao) or (va cham)) xuc van hanh ki su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) uu lang dai hoi. hieu ((va cao) or (va cham)) xuc van hanh ki su triet*.