Perhaps you should try some spelling variations:
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
cam hoc » cao hoc, am hoc, cam hoa
vai cua » dai cua, hai cua, lai cua
hoc ban » hoc bang, hoc dan, hoc bai
van cam » van nam, van lam, van cau
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
di cua » dai cua, doi cua, de cua

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 lang) or (ky dang)) xa hoi. hieu van cam hoc ban hanh ((di cua) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky lang) OR (ky dang)) xa hoi. hieu van cam hoc ban hanh ((di cua) OR (vai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: su sach ((ky lang) or (ky dang)) xa hoi. hieu van cam hoc ban hanh ((di cua) or (vai cua)) tre*.