Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh ve » hanh ve, thanh va, thanh vien
phuc ban » phuc van, thuc ban, thuoc ban
cau phuc » cau truc, chau phu, huu phuc
van cau » van dau, van hau, van chat
ky lang » ky dang, ky tang, tay lang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
ve cua » le cua, de cua, te cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (su sach)) ((ky lang) or (ky nang)) xa hoi. hieu van cau phuc ban thanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ((ky lang) OR (ky nang)) xa hoi. hieu van cau phuc ban thanh ve cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ((ky lang) or (ky nang)) xa hoi. hieu van cau phuc ban thanh ve cua tre*.