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 ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((van nang) OR (van dong)) xa hoi. hieu ve cam truc van hanh ((vi cua) OR (di cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((van nang) OR (van dong)) xa hoi. hieu ve 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 ve cam truc van hanh ((vi cua) or (di cua)) tre*.