Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
su sach » so sach, vu sach
ty nang » ty xang, ty hang, ly nang
hieu ve » hieu va, hieu van
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
va hoa » van hoa, va hoc, ma hoa

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 ((ty nang) OR (ky nang)) xa hoi. hieu ve ((cam tuc) or (nam thuoc)) va hanh va hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty nang) OR (ky nang)) xa hoi. hieu ve ((cam tuc) OR (nam thuoc)) va hanh va hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty nang) OR (ky nang)) xa hoi. hieu ve ((cam tuc) or (nam thuoc)) va hanh va hoa viet".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty nang) OR (ky nang)) xa hoi. hieu ve ((cam tuc) or (nam thuoc)) va hanh va hoa viet*.