Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
doan vi » doan va, don vi, doan thi
y nang » ky nang, v nang, may nang
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((y nang) OR (ly nang)) xa hoi. hieu ve cac tu va ((gan vi) or (doan vi)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((y nang) OR (ly nang)) xa hoi. hieu ve cac tu va ((gan vi) OR (doan vi)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((y nang) OR (ly nang)) xa hoi. hieu ve cac tu va ((gan vi) or (doan vi)) cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ((y nang) OR (ly nang)) xa hoi. hieu ve cac tu va ((gan vi) or (doan vi)) cua triet*.