Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh tai, thanh oai
thanh van » thanh san, thanh toan, thanh phan
so sach » so sanh, bo sach, co sach
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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 y nang xa hoi. ((hieu va) or (lieu va)) cao duc van ((thanh vai) OR (thanh van)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang xa hoi. ((hieu va) OR (lieu va)) cao duc van ((thanh vai) OR (thanh van)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang xa hoi. ((hieu va) or (lieu va)) cao duc van ((thanh vai) OR (thanh van)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. ((hieu va) or (lieu va)) cao duc van ((thanh vai) OR (thanh van)) cua tre*.