Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thanh vi » hanh vi, thanh va, thanh ve
xa thanh » va thanh, ha thanh, ta thanh
cac toc » cac toi, cac nuoc, cac thoi
cac tac » cac bac, cac dac, cac tai
hieu ve » hieu va, hieu van
tu sach » thu sach, te sach, tu cach
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai
vi su » va su, ve su, ki su

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) or (su sach)) ty nang o hai. hieu ve ((cac tac) OR (cac toc)) xa thanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty nang o hai. hieu ve ((cac tac) OR (cac toc)) xa thanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ty nang o hai. hieu ve ((cac tac) OR (cac toc)) xa thanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ty nang o hai. hieu ve ((cac tac) OR (cac toc)) xa thanh vi su triet*.