Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
tham duc » pham duc, tham du, than duc
van tham » van thanh, van tuan, van chat
sach ty » sach y, sach tu, sach thu
duc ban » duc tan, duc van, dua ban
ty nang » ky nang, ty xang, ty hang
hai cua » thai cua, dai cua, lai cua
hoi cua » hoi chuc
su sach » so sach, vu sach
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 ty nang ((x hoi) OR (xa hoi)). hieu van tham duc ban hanh ((hai cua) or (hoi cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((x hoi) OR (xa hoi)). hieu van tham duc ban hanh ((hai cua) OR (hoi cua)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((x hoi) OR (xa hoi)). hieu van tham duc ban hanh ((hai cua) or (hoi cua)) triet*".