Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, cua khach
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va tinh » may tinh
tinh vi » trinh vi, tinh voi, tinh va
va cao » va cac, va co, va dao
vi cau » va cau, ve cau, di cau
x hoi » xa hoi, o hoi, x ho

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) or (((vu khach) OR (vay khach)))) ky nang x hoi. hieu va cao duc va tinh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (((vu khach) OR (vay khach)))) ky nang x hoi. hieu va cao duc va tinh vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (((vu khach) OR (vay khach)))) ky nang x hoi. hieu va cao duc va tinh vi cau tren".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (((vu khach) OR (vay khach)))) ky nang x hoi. hieu va cao duc va tinh vi cau tren*.