Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
su sach » so sach, vu sach
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
vi va » vi van, vai va, vu va

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 ((y lang) OR (_ lang)) xa hoi. hieu van ((cam tuc) or (nam thuoc)) va hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y lang) OR (_ lang)) xa hoi. hieu van ((cam tuc) OR (nam thuoc)) va hanh vi va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y lang) OR (_ lang)) xa hoi. hieu van ((cam tuc) or (nam thuoc)) va hanh vi va triet*".