Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
cau tren » cu tren, dau tren, ca tren
vu khach » vu khanh, vu khac, vay khach
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
ve cac » va cac, vien cac
ve cao » va cao, ve bao, ve co
su va » su van, tu va
x hoi » xa hoi, o hoi, x ho

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) OR (vu khach)) ky nang x hoi. hieu ((ve cao) OR (ve cac)) su va thanh dat cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu khach)) ky nang x hoi. hieu ((ve cao) OR (ve cac)) su va thanh dat cau tren~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu khach)) ky nang x hoi. hieu ((ve cao) OR (ve cac)) su va thanh dat cau tren*.