Perhaps you should try some spelling variations:
hieu triet » hieu tiem, hieu tren
hau triet » cau triet, hanh triet, khac triet
hanh hai » thanh hai, nhanh hai, hang hai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
qua cac » cua cac
cac luc » cau luc, coc luc, cac nuoc
va hanh » van hanh, va thanh, va danh
nang o » nang co, nang ho, nang ro
luc va » duc va, tuc va, loc va
o hoc » co hoc, mo hoc, so hoc

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 ky nang o hoc. hieu qua cac luc va hanh hai ((hau triet) or (hieu triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang o hoc. hieu qua cac luc va hanh hai ((hau triet) OR (hieu triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang o hoc. hieu qua cac luc va hanh hai ((hau triet) or (hieu triet))*.