Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cham sat » cham mat, cham soc, giam sat
sang cua » mang cua, hang cua, tang cua
song cua » cong cua, dong cua, huong cua
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu vu » hieu va, hieu ve, hieu su
khao » khac, khai, thao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky dang xa hoi. hieu vu ((cham sat) OR (khao sat)) van thanh ((sang cua) or (song cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky dang xa hoi. hieu vu ((cham sat) OR (khao sat)) van thanh ((sang cua) OR (song cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky dang xa hoi. hieu vu ((cham sat) OR (khao sat)) van thanh ((sang cua) or (song cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky dang xa hoi. hieu vu ((cham sat) OR (khao sat)) van thanh ((sang cua) or (song cua)) tre*.