Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cao hoat » cac hoat, co hoat, cao chat
viec cac » viec cua, viec lam, viec va
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, su sach, te sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
va hang » van hang, va nang, va lang
cua tre » cua te, cuu tre, dua tren

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 ly nang cao hoat. hieu ((viec cac) or (vien cac)) tu va hang va ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly nang cao hoat. hieu ((viec cac) OR (vien cac)) tu va hang va ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly nang cao hoat. hieu ((viec cac) or (vien cac)) tu va hang va ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ly nang cao hoat. hieu ((viec cac) or (vien cac)) tu va hang va ((cua tre) OR (cua triet))*.