Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
xang mai » lang mai, sang mai, hoang mai
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, dam thuc
hieu ve » hieu va, hieu van
sach ty » sach tu, sach thu, xach tay
mai hoi » mai khoi, dai hoi, lai hoi
vi hoc » li hoc, va hoc
hien » bien, vien, tien

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo ((sach ty) or (sach y)) xang mai hoi. hieu ve ((cam tuc) OR (nam thuc)) va hanh vi hoc hien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo ((sach ty) OR (sach y)) xang mai hoi. hieu ve ((cam tuc) OR (nam thuc)) va hanh vi hoc hien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo ((sach ty) or (sach y)) xang mai hoi. hieu ve ((cam tuc) OR (nam thuc)) va hanh vi hoc hien".
• Adding a wildcard symbol may retrieve word variants: bo ((sach ty) or (sach y)) xang mai hoi. hieu ve ((cam tuc) OR (nam thuc)) va hanh vi hoc hien*.