Perhaps you should try some spelling variations:
thanh vinh » thanh binh, than kinh, thanh van
thanh tinh » thanh binh, nhanh tinh, than kinh
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
nam tuc » nam thuc, nam truc, nam tu
tuc gia » tac gia, duc gia, toc gia
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, 5 hoi

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) or (x ho)). hieu van nam tuc gia ((thanh vinh) or (thanh tinh)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((x hoi) OR (x ho)). hieu van nam tuc gia ((thanh vinh) OR (thanh tinh)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((x hoi) or (x ho)). hieu van nam tuc gia ((thanh vinh) or (thanh tinh)) cuu tre*.