Perhaps you should try some spelling variations:
sach duoc » sach nuoc, sach dao, sach dung
duoc nang » duoc nhung, dun nang, dung nang
ve triet » va trien
su triet » su viet, su tien
van hanh » van thanh, ban hanh, van anh
hanh ki » hanh vi, hanh ky, hanh kien
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
va cam » va cham, va cac, va cao
ma hoi » mai hoi, xa hoi, ma hoa
va co » vo co

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 duoc nang ma hoi. hieu ((va cam) or (va co)) xuc van hanh ki ((su triet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach duoc nang ma hoi. hieu ((va cam) OR (va co)) xuc van hanh ki ((su triet) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach duoc nang ma hoi. hieu ((va cam) or (va co)) xuc van hanh ki ((su triet) or (ve triet))*.