Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
va dau » va dao
tu van » tu va
di cuu » di cua, dinh cuu
di cau » da cau, diem cau
x hoi » xa hoi, o hoi, x ho

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. lieu va dau tu van hanh ((di cuu) or (di cau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu nang x hoi. lieu va dau tu van hanh ((di cuu) OR (di cau)) tre*.