Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
thi nang » thi cong, ki nang, thi hanh
te sach » toc sach
luc ban » duc ban, cuc ban, luc bat
cac luc » cau luc, coc luc, cac nuoc
van cac » van hac, van cau, van bac
ty hang » ly hang, ty xang, thi hang
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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 ((ty hang) or (thi nang)) x hoi. hieu van cac luc ban thanh ((di cua) OR (de cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ty hang) OR (thi nang)) x hoi. hieu van cac luc ban thanh ((di cua) OR (de cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ty hang) or (thi nang)) x hoi. hieu van cac luc ban thanh ((di cua) OR (de cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ty hang) or (thi nang)) x hoi. hieu van cac luc ban thanh ((di cua) OR (de cua)) tre*.