Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
ly quang » le quang, vu quang
va trien » va truyen, va tuyen, va tieng
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
ly vang » ly hang, ly van
ve nam » he nam, va nam, le nam
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 quang) or (ly vang)) xa hoi. hieu ve 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 quang) OR (ly vang)) xa hoi. hieu ve nam thuc va hanh vi ((va trien) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: su sach ((ly quang) or (ly vang)) xa hoi. hieu ve nam thuc va hanh vi ((va trien) or (va thiet))*.