Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
thanh le » thinh le, thanh ve, thanh de
thuc ban » thuoc ban, thuc dan, thu ban
hai thuc » thai thuc, dai thuc, ha thuc
van hai » van ha, van chat, van hanh
hoc anh » hoc nganh, hoc nhanh, ngoc anh
ky lang » ky dang, ky tang, tay lang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
le cua » ly cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc anh) OR (su sach)) ((ky lang) OR (ky nang)) xa hoi. hieu van hai thuc ban thanh le cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc anh) OR (su sach)) ((ky lang) OR (ky nang)) xa hoi. hieu van hai thuc ban thanh le cua tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc anh) OR (su sach)) ((ky lang) OR (ky nang)) xa hoi. hieu van hai thuc ban thanh le cua tre*.