Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
thu nang » thi nang, thu hang, thu bang
thuc dan » thuc hanh, hoc dan, thuc vat
sach thu » sach thue, sach thieu, sach tham
hanh va » hang va, hanh vi
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve nam » he nam, va nam, le nam
x hoi » o hoi, x ho, 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 thu nang ((x hoi) OR (xa hoi)). hieu ve nam thuc dan ((hanh va) or (hanh kem)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang ((x hoi) OR (xa hoi)). hieu ve nam thuc dan ((hanh va) OR (hanh kem)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu nang ((x hoi) OR (xa hoi)). hieu ve nam thuc dan ((hanh va) or (hanh kem)) cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang ((x hoi) OR (xa hoi)). hieu ve nam thuc dan ((hanh va) or (hanh kem)) cua viet*.