Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
hanh dao » lanh dao, thanh dat, thanh dam
dang xay » dang van, van xay
cua tre » cua te, cuu tre, dua tren
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu le » hieu ve, hieu he, hieu ly
nang xa » nang x, lang xa, nang ma
le nam » ly nam, he nam, le na

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 ((nang xa) or (dang xay)) hoi. hieu le nam thuc va hanh dao ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (dang xay)) hoi. hieu le nam thuc va hanh dao ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (dang xay)) hoi. hieu le nam thuc va hanh dao ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (dang xay)) hoi. hieu le nam thuc va hanh dao ((cua tre) OR (cua triet))*.