Perhaps you should try some spelling variations:
toan hanh » toan thanh, toan anh, tran hanh
ve triet » va trien, su triet
sach thu » sach thue, sach thieu, sach tham
tan hanh » tan thanh, tang hanh, tran hanh
tham duc » pham duc, tham du, than duc
van tham » van thanh, van tuan, van chat
hieu van » hieu va, thien van, lieu va
thu bang » thu ban, thu hang, chu bang
su sach » so sach, vu sach
lai ve » loai ve, lai va, la ve
o hoi » co hoi, o hoc, o hai
x hoi » xa 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 bang ((x hoi) or (o hoi)). hieu van tham duc ((tan hanh) OR (toan hanh)) lai ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu bang ((x hoi) OR (o hoi)). hieu van tham duc ((tan hanh) OR (toan hanh)) lai ve triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu bang ((x hoi) or (o hoi)). hieu van tham duc ((tan hanh) OR (toan hanh)) lai ve triet*".