Perhaps you should try some spelling variations:
ve triet » va trien, su triet
hanh doi » thanh doi, hanh noi, hang doi
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, va danh
cac luc » cau luc, coc luc, cac cuoc
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
su hai » su tai
doi ve » moi ve, doi va, noi ve
su sai » su tai, su dai, su mai

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

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