Perhaps you should try some spelling variations:
van nang » van quang, van ban, van dung
cam truc » cau truc, nam truc, lam truoc
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
vi cua » vai cua
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 ((van nang) or (van dong)) xa hoi. hieu va cam truc van hanh ((vi cua) or (di cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((van nang) OR (van dong)) xa hoi. hieu va cam truc van hanh ((vi cua) OR (di cua)) tre.
• Adding a wildcard symbol may retrieve word variants: su sach ((van nang) or (van dong)) xa hoi. hieu va cam truc van hanh ((vi cua) or (di cua)) tre*.