Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
va xanh » va danh, va hanh, va anh
xanh di » danh di, vanh dai, xanh tai
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sach ty)) nang ((x hoi) OR (o hoi)). hieu van cau truc va xanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang ((x hoi) OR (o hoi)). hieu van cau truc va xanh di cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sach ty)) nang ((x hoi) OR (o hoi)). hieu van cau truc va xanh di cua viet*".