Perhaps you should try some spelling variations:
van phan » van phong, van thanh, luan phan
van cham » van chat, van tham, van pham
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
va cham » va chat, va tham
tai va » thai va, mai va, tri va
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: tu sach ty nang xa hoi. hieu ((van cham) OR (va cham)) xuc ((van hanh) or (van phan)) tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu ((van cham) OR (va cham)) xuc ((van hanh) OR (van phan)) tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu ((van cham) OR (va cham)) xuc ((van hanh) or (van phan)) tai va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu ((van cham) OR (va cham)) xuc ((van hanh) or (van phan)) tai va thiet*.