Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
hanh doi » thanh doi, hanh noi, hang doi
hoc sach » hoc sinh, hoc cac, hoc anh
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
vu sach » vu bach, su sach, vu khach
hieu ve » hieu va
toc va » hoc va, toc ta, tuc va
doi va » hoi va, noi va, dai 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 (hoc sach)) ky nang x ho. ((hieu ve) OR (hieu van)) cac toc va hanh doi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (hoc sach)) ky nang x ho. ((hieu ve) OR (hieu van)) cac toc va hanh doi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (hoc sach)) ky nang x ho. ((hieu ve) OR (hieu van)) cac toc va hanh doi va triet".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (hoc sach)) ky nang x ho. ((hieu ve) OR (hieu van)) cac toc va hanh doi va triet*.