Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thai cuu » thai cua, thi cuc, thai xu
vu sach » vu bach, vu khach
su sach » so sach
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
van bac » van ban, van bao, van hac
va danh » va dinh, va dan, va hanh

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (su sach)) ty nang xa hoi. hieu van bac duc va danh ((thai cuu) OR (tai cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ty nang xa hoi. hieu van bac duc va danh ((thai cuu) OR (tai cuc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ty nang xa hoi. hieu van bac duc va danh ((thai cuu) OR (tai cuc)) tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ty nang xa hoi. hieu van bac duc va danh ((thai cuu) OR (tai cuc)) tre*.