Perhaps you should try some spelling variations:
va trien » va truyen, va tuyen, va tieng
nam thuc » nam thuoc, am thuc, nam thu
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach y, sach lo, sach ty
hieu le » hieu ve, hieu he, hieu ly
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
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 ma) or (sang ma)) hoi. hieu le nam thuc va hanh vi ((va trien) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly ((nang ma) OR (sang ma)) hoi. hieu le nam thuc va hanh vi ((va trien) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: su sach ly ((nang ma) or (sang ma)) hoi. hieu le nam thuc va hanh vi ((va trien) or (va thiet))*.