Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
thi hong » thi cong, thi phuong, thi hanh
tinh di » tinh doi, trinh di, tinh da
van cac » van hac, van cau, van bac
luc va » tuc va, loc va
hong x » hong _, thong xu, phong xa
di cua » dai cua, doi cua, de 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) or (toc sach)) thi hong x hoi. hieu van cac ((luc va) OR (duc va)) tinh di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) thi hong x hoi. hieu van cac ((luc va) OR (duc va)) tinh di cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) thi hong x hoi. hieu van cac ((luc va) OR (duc va)) tinh di cua vat".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) thi hong x hoi. hieu van cac ((luc va) OR (duc va)) tinh di cua vat*.