Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
manh vai » manh hai, manh khai, hanh vi
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
manh va » hanh va, anh va, minh va
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
ve nam » he nam, va nam, le nam
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang ((o hoi) or (o hai)). hieu ve nam thuc dan ((manh vai) OR (manh va)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((o hoi) OR (o hai)). hieu ve nam thuc dan ((manh vai) OR (manh va)) cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((o hoi) or (o hai)). hieu ve nam thuc dan ((manh vai) OR (manh va)) cua viet*".