Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
xa thanh » va thanh, ha thanh, ta thanh
hieu ve » hieu va, hieu van
cac tac » cac bac, cac dac, cac tai
sach ty » sach y, sach tu, sach thu
cac toc » cac toi, cac nuoc, cac thoi
ty nang » ky nang, ty xang, ty hang
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai
vi su » va su, ve su, oi su
ki su » ky su

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

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