Perhaps you should try some spelling variations:
dung cong » dung trong
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang xa hoi. hieu van cam ((xuc van) OR (duc van)) dung cong ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. hieu van cam ((xuc van) OR (duc van)) dung cong ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang xa hoi. hieu van cam ((xuc van) OR (duc van)) dung cong ((cua tre) or (cuu tre))*".