Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
hang di » hang doi, hang vi, hang dien
tuc va » thuc va, truc va, duc va
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, 5 hoi

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 ((x hoi) or (x ho)). hieu van cau ((tuc va) OR (tuc xa)) hang di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu van cau ((tuc va) OR (tuc xa)) hang di cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (x ho)). hieu van cau ((tuc va) OR (tuc xa)) hang di cua viet*".