Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cuc viet » chuc viet, tuc viet, cua viet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
duc ban » duc tan, duc van, duc manh
duc man » duc manh, duc tan, duc mau
dua ban » dia ban, cua ban, qua ban
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 ky nang x hoi. hieu van cham ((((duc ban) OR (duc man))) or (dua ban)) thanh tai cuc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu van cham ((((duc ban) OR (duc man))) OR (dua ban)) thanh tai cuc viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu van cham ((((duc ban) OR (duc man))) or (dua ban)) thanh tai cuc viet".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu van cham ((((duc ban) OR (duc man))) or (dua ban)) thanh tai cuc viet*.