Perhaps you should try some spelling variations:
duc tien » duc thien, luc tieng, thuc tien
ly quang » le quang, vu quang
hanh tai » thanh tai, hang tai, han tai
bo sach » hoc sach
hieu va » lieu va, hieu qua
cac tru » ca tru, cac tro, cac thu
va hanh » van hanh, va thanh, va danh
tai duc » tai cuc, mai duc, tai du
co sach » cuon sach, hoc sach
tru va » truc va, tu va, trung va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((co sach) OR (bo sach)) ((ly hang) or (ly quang)) xa hoi. hieu va cac tru va hanh tai duc tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (bo sach)) ((ly hang) OR (ly quang)) xa hoi. hieu va cac tru va hanh tai duc tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((co sach) OR (bo sach)) ((ly hang) or (ly quang)) xa hoi. hieu va cac tru va hanh tai duc tien".
• Adding a wildcard symbol may retrieve word variants: ((co sach) OR (bo sach)) ((ly hang) or (ly quang)) xa hoi. hieu va cac tru va hanh tai duc tien*.