Perhaps you should try some spelling variations:
dua tren » dung tren
vu khach » vu khanh, vu khac, vay khach
dao duc » giao duc, tao duoc
cu tren » tu tren
tinh ve » trinh ve, tinh ven, dinh ve
va tinh » may tinh
vu sach » vu bach, su sach
hieu va » lieu va, hieu qua
va dao » ca dao
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: ((vu sach) or (vu khach)) ky nang x hoi. hieu va dao duc va tinh ve ((cu tren) OR (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ky nang x hoi. hieu va dao duc va tinh ve ((cu tren) OR (dua tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (vu khach)) ky nang x hoi. hieu va dao duc va tinh ve ((cu tren) OR (dua tren))".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khach)) ky nang x hoi. hieu va dao duc va tinh ve ((cu tren) OR (dua tren))*.