Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van thanh » ban thanh, van tuan
hoang van » hang va
van hanh » ban hanh, van anh, van ban
va nang » van nang, da nang, cam nang
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
vi cua » vai cua, di cua

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 y ((nang xa) or (hoang van)) hoi. hieu va nang luc ((van hanh) OR (van thanh)) vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (hoang van)) hoi. hieu va nang luc ((van hanh) OR (van thanh)) vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) or (hoang van)) hoi. hieu va nang luc ((van hanh) OR (van thanh)) vi cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (hoang van)) hoi. hieu va nang luc ((van hanh) OR (van thanh)) vi cua triet*.