Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
dau truc » cau truc, dai truc, doan truc
truc ban » thuc ban, truc dan, truc van
thanh va » thanh van, hanh va, thanh ha
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van dau » van dao, phan dau
cua tre » cua te, cuu tre, cua triet

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 dau truc ban thanh va ((cua tre) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu van dau truc ban thanh va ((cua tre) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu van dau truc ban thanh va ((cua tre) or (cua vat))*.