Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thue nang » thien nang, thuat nang, thi nang
cua viet » ca viet, hoa viet, cua vat
than duc » phan duc, than doc, than luc
hanh lai » hanh lam, hanh tai, thanh lap
ban hanh » ban hang
lai cua » dai cua, hai cua, lai chau
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
x hoi » o hoi, x ho, 5 hoi

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 thue nang ((x hoi) or (xa hoi)). hieu va ((than duc) OR (tran duc)) ban hanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thue nang ((x hoi) OR (xa hoi)). hieu va ((than duc) OR (tran duc)) ban hanh lai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thue nang ((x hoi) or (xa hoi)). hieu va ((than duc) OR (tran duc)) ban hanh lai cua viet".
• Adding a wildcard symbol may retrieve word variants: su sach thue nang ((x hoi) or (xa hoi)). hieu va ((than duc) OR (tran duc)) ban hanh lai cua viet*.