Perhaps you should try some spelling variations:
thanh vai » thanh van, thanh tai, thanh oai
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
dua ban » dia ban, cua ban, qua ban
van cau » van dau, van hau, van chat
cau dua » cau qua, cau cua, ca dua
tao hoi » tao khoi, tao boi, tay hoi
tao hoa » bao hoa, tao ho, tao hop
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky sang ((tao hoa) OR (tao hoi)). hieu van cau dua ban ((thanh vai) or (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky sang ((tao hoa) OR (tao hoi)). hieu van cau dua ban ((thanh vai) OR (thanh hai)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky sang ((tao hoa) OR (tao hoi)). hieu van cau dua ban ((thanh vai) or (thanh hai)) cua tre*".