Perhaps you should try some spelling variations:
xang mai » lang mai, sang mai, hoang mai
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach, vu sach
tu xang » ty xang, tu lang, tu quang
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
sach tu » sach thu, cach tu, sach ty
cam luc » cau luc
va hanh » van hanh, va thanh, va danh
vai va » mai va, dai va, hai va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu xang mai hoi. ((hieu ve) or (hieu qua)) ((cam luc) OR (cam xuc)) va hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu xang mai hoi. ((hieu ve) OR (hieu qua)) ((cam luc) OR (cam xuc)) va hanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu xang mai hoi. ((hieu ve) or (hieu qua)) ((cam luc) OR (cam xuc)) va hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach tu xang mai hoi. ((hieu ve) or (hieu qua)) ((cam luc) OR (cam xuc)) va hanh vai va thiet*.