Perhaps you should try some spelling variations:
chau viet » chu viet, khau viet, cham viet
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
phan duc » pham duc, phan tu, phan dau
tan hanh » tan thanh, tang hanh, toan hanh
hanh lai » hanh lam, hanh tai, thanh lap
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
va phan » van phan, va phat, va phap
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 thu nang ((x hoi) or (xa hoi)). hieu va phan duc tan hanh lai chau viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu nang ((x hoi) OR (xa hoi)). hieu va phan duc tan hanh lai chau viet.
• Adding a wildcard symbol may retrieve word variants: su sach thu nang ((x hoi) or (xa hoi)). hieu va phan duc tan hanh lai chau viet*.