Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
thanh di » thanh doi, thanh de, thanh do
nang xa » nang x, lang xa, nang ma
van bac » van ban, van bao, van hac
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
tu van » tu va
va bac » va cac, va bai, va bao

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

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