Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
nang mai » nang ma, nang tai, lang mai
va triet » va trien, ve triet, cua triet
su sach » so sach, vu sach
hanh va » hanh vi
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach y, sach lo, sach ty
hieu le » hieu ve, hieu he, hieu ly
mai hoi » mai khoi, dai hoi, lai hoi
ly nang » ky nang, ly hang, ly vang
le nam » ly nam, he nam, le na
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 mai hoi. hieu le nam thuc va ((hanh va) OR (hang va)) ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang mai hoi. hieu le nam thuc va ((hanh va) OR (hang va)) ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly nang mai hoi. hieu le nam thuc va ((hanh va) OR (hang va)) ((va triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: su sach ly nang mai hoi. hieu le nam thuc va ((hanh va) OR (hang va)) ((va triet) or (va thiet))*.