Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
chau tre » chay tren, chau tho, cho tre
cao hoi » cau hoi, co hoi, tao hoi
cao hoc » co hoc, cho hoc, chat hoc
va chat » van chat, va phat, hoa chat
xuc van » duc van, luc van, vuc van
tu sai » tu bai, tu san, tu cai
sai ky » sac ky

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky nang ((cao hoi) or (cao hoc)). thien ((va chat) OR (cao chat)) xuc van hanh lai chau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky nang ((cao hoi) OR (cao hoc)). thien ((va chat) OR (cao chat)) xuc van hanh lai chau tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky nang ((cao hoi) or (cao hoc)). thien ((va chat) OR (cao chat)) xuc van hanh lai chau tre".
• Adding a wildcard symbol may retrieve word variants: tu sai ky nang ((cao hoi) or (cao hoc)). thien ((va chat) OR (cao chat)) xuc van hanh lai chau tre*.