Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
vai cua » dai cua, hai cua, lai cua
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
tuc va » truc va, tuc xa, duc 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 dang) or (ky tang)) xa hoi. hieu va cac ((tuc va) OR (thuc va)) dan vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky tang)) xa hoi. hieu va cac ((tuc va) OR (thuc va)) dan vai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky tang)) xa hoi. hieu va cac ((tuc va) OR (thuc va)) dan vai cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky tang)) xa hoi. hieu va cac ((tuc va) OR (thuc va)) dan vai cua triet*.