Perhaps you should try some spelling variations:
su sach » so sach, vu sach
van tai » von tai, van tuan
va chat » van chat, va phat, cao chat
ve cham » va cham, ve chat, vu cham
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
luc va » duc va, tuc va, loc va
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: su sach ((ty nang) or (ty hang)) xa hoi. hieu ((ve cham) or (va chat)) luc va van tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty nang) OR (ty hang)) xa hoi. hieu ((ve cham) OR (va chat)) luc va van tai va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ((ty nang) or (ty hang)) xa hoi. hieu ((ve cham) or (va chat)) luc va van tai va thiet*.