Perhaps you should try some spelling variations:
chet duoc » cho duoc, che quoc, chi duoc
thanh va » thanh van, hanh va, thanh ha
va thanh » gia thanh, ban thanh, va tinh
che duoc » che thuoc, che do, te duoc
va triet » va thiet, va trien, ve triet
hieu va » lieu va, hieu qua
te sach » toc sach
so sach » so sanh, bo sach, co sach
x hoi » xa hoi, o hoi, x ho
va va » va van, va vua, va vai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) or (te sach)) ky nang x hoi. hieu va ((chet duoc) OR (che duoc)) va thanh va va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (te sach)) ky nang x hoi. hieu va ((chet duoc) OR (che duoc)) va thanh va va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (te sach)) ky nang x hoi. hieu va ((chet duoc) OR (che duoc)) va thanh va va triet".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (te sach)) ky nang x hoi. hieu va ((chet duoc) OR (che duoc)) va thanh va va triet*.