Perhaps you should try some spelling variations:
thien van » thi van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
chao tu » chao xu, cho tu, cao tu
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
va va » va van, va vua, va vai
thiet » thieu

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 ve) or (thien van)) chao tu va hanh va va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. ((hieu ve) OR (thien van)) chao tu va hanh va va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. ((hieu ve) or (thien van)) chao tu va hanh va va thiet*.