Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh tai, thanh oai
thanh van » thanh san, thanh toan, thanh phan
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
van bao » van ban, van dao
bao duc » dao duc, bao luc, cao duc
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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 y nang x hoi. hieu van bao duc van ((thanh vai) or (thanh van)) ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu van bao duc van ((thanh vai) OR (thanh van)) ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu van bao duc van ((thanh vai) or (thanh van)) ((cua tre) or (cau tren))*.