Perhaps you should try some spelling variations:
thanh sang » thanh san, thanh hang, thanh hoang
van thanh » ban thanh, van tuan
dang xay » dang van, van xay
sang cua » mang cua, song cua, hang cua
khai sat » khao sat, khai quat, khai sang
qua khai » qua hai, quang khai, quan hai
sat van » sat va, hat van, hoat van
cua tre » cua te, cuu tre, cua triet
dang xa » lang xa, dang ha, dang va
tu san » thu san, tu ban, tu can
tu sac » tu sach, tu cac, tu bac

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) or (tu san)) ky ((dang xa) or (dang xay)) hoi. hieu qua khai sat van thanh sang cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu san)) ky ((dang xa) OR (dang xay)) hoi. hieu qua khai sat van thanh sang cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu san)) ky ((dang xa) or (dang xay)) hoi. hieu qua khai sat van thanh sang cua tre*.