Perhaps you should try some spelling variations:
thuc tien » thuc hien
duc tien » duc thien, luc tieng, doc tieng
hanh tai » thanh tai, hang tai, han tai
ly quang » le quang, vu quang
va hanh » van hanh, va thanh, va danh
co sach » bo sach, cuon sach, hoc sach
hieu va » lieu va, hieu qua
cac tru » ca tru, cac tro, cac thu
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 ((ly hang) or (ly quang)) xa hoi. hieu va cac tru va hanh tai ((duc tien) OR (thuc tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((ly hang) OR (ly quang)) xa hoi. hieu va cac tru va hanh tai ((duc tien) OR (thuc tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((ly hang) or (ly quang)) xa hoi. hieu va cac tru va hanh tai ((duc tien) OR (thuc tien))".
• Adding a wildcard symbol may retrieve word variants: co sach ((ly hang) or (ly quang)) xa hoi. hieu va cac tru va hanh tai ((duc tien) OR (thuc tien))*.