Perhaps you should try some spelling variations:
nang doc » nang luc
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang co » nang cao, nang noi, nang hoc
hieu va » lieu va, hieu qua
va am » va lam, va cam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang co) OR (nang doc)) hoi. hieu va am thuc va danh ((vai cua) OR (lai cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang co) OR (nang doc)) hoi. hieu va am thuc va danh ((vai cua) or (lai cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang co) OR (nang doc)) hoi. hieu va am thuc va danh ((vai cua) or (lai cua)) triet*.