Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc day » thuc dan, thuc vat
nhanh va » hanh va, nhan va, nhanh ha
su sach » so sach, vu sach
ly nang » ly hang, ly vang, ly quang
ma hoi » mai hoi, xa hoi, ma hoa
thiet » thieu

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 ((ly nang) OR (ky nang)) ma hoi. hieu van nam thuc day nhanh va ((cua triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly nang) OR (ky nang)) ma hoi. hieu van nam thuc day nhanh va ((cua triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ly nang) OR (ky nang)) ma hoi. hieu van nam thuc day nhanh va ((cua triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ly nang) OR (ky nang)) ma hoi. hieu van nam thuc day nhanh va ((cua triet) or (va thiet))*.