Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
thien hach » thien thanh, hien hanh
cua triet » cua viet, su triet, va triet
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hach lo » sach lo, hoach do
va dinh » van dinh, va kinh, va tinh
dinh va » dinh van, dinh ve, tinh va
lo va » lo van, lao va, ly va

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 ky nang x ho. hieu thien hach lo va dinh va ((dua tren) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x ho. hieu thien hach lo va dinh va ((dua tren) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu thien hach lo va dinh va ((dua tren) or (cua triet))*.