Perhaps you should try some spelling variations:
ve triet » va trien
duc manh » suc manh, duc anh, duc minh
nang mai » nang ma, nang tai, lang mai
su triet » su viet, su tien
thanh ki » thanh kim, thanh ky, thanh ke
su sach » so sach, vu sach
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
vu nang » vuc nang, va nang, vu dang
duc van » duc va, duc tan, duc phan
va cao » va cac, va co, va dao

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 vu nang mai hoi. hieu va cao ((duc van) or (duc manh)) thanh ki ((su triet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach vu nang mai hoi. hieu va cao ((duc van) OR (duc manh)) thanh ki ((su triet) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: su sach vu nang mai hoi. hieu va cao ((duc van) or (duc manh)) thanh ki ((su triet) or (ve triet))*.