Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dang xay » dang van, van xay
cua tre » cua te, cuu tre, dua tren
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cac luc » cau luc, coc luc, cac nuoc
vu sach » vu bach, vu khach
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
su sach » so sach
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (su sach)) ky dang xay hoi. hieu ve cac luc va hanh va ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky dang xay hoi. hieu ve cac luc va hanh va ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ky dang xay hoi. hieu ve cac luc va hanh va ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ky dang xay hoi. hieu ve cac luc va hanh va ((cua tre) OR (cua triet))*.