Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dua tren » dung tren
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
su sach » so sach, vu sach
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
cao duc » dao duc, cao suc, tao duoc
nang xa » nang x, lang xa, nang ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang xa hoi. hieu van ((cao duc) OR (giao duc)) ban thanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu van ((cao duc) OR (giao duc)) ban thanh vi ((dua tren) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. hieu van ((cao duc) OR (giao duc)) ban thanh vi ((dua tren) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu van ((cao duc) OR (giao duc)) ban thanh vi ((dua tren) or (cuu tre))*.