Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
thai cuu » thai cua, tai cuc, thai xu
thi cuc » tai cuc
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau

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

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