Perhaps you should try some spelling variations:
ve triet » va trien, su triet
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, ve cai
va dan » ca dan, va dao, va dau
hoi ve » hoi va, moi ve, noi ve
va cam » va cham, va cac, va cao

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

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