Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
hoa hoi » khoa hoi, hoa hoc, hoa doi
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
ky lang » ky dang, ky tang, tay lang
tu sach » thu sach, su sach, te sach
va nam » van nam, ha nam, va nay

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 lang) or (ky nang)) hoa hoi. hieu va nam thuc day hanh va ((cua triet) OR (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky nang)) hoa hoi. hieu va nam thuc day hanh va ((cua triet) OR (va triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) or (ky nang)) hoa hoi. hieu va nam thuc day hanh va ((cua triet) OR (va triet))*".