Perhaps you should try some spelling variations:
hai truc » dai truc, hai trac, hang truc
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va hai » van hai, va chai, va khai
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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. lieu va hai truc ((ban hanh) or (van hanh)) ((vi cua) OR (di cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. lieu va hai truc ((ban hanh) OR (van hanh)) ((vi cua) OR (di cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. lieu va hai truc ((ban hanh) or (van hanh)) ((vi cua) OR (di cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. lieu va hai truc ((ban hanh) or (van hanh)) ((vi cua) OR (di cua)) tre*.