Perhaps you should try some spelling variations:
van nhan » van phan, van thanh, danh nhan
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va cham » va chat
va tham » van tham, va thanh, va thuat
van han » van hanh, van phan, van hoan
tai va » thai va, mai va, tri va
x hoi » xa hoi, o hoi, x ho
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 x hoi. hieu ((va cham) OR (va tham)) vuc ((van han) or (van nhan)) tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu ((va cham) OR (va tham)) vuc ((van han) OR (van nhan)) tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu ((va cham) OR (va tham)) vuc ((van han) or (van nhan)) tai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu ((va cham) OR (va tham)) vuc ((van han) or (van nhan)) tai va thiet*.