Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thai cuu » thai cua, tai cuc, thai xu
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
thi cuc » tai cuc
truc va » thuc va, thuc vat, trung va
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, tuc xa, duc va

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