Perhaps you should try some spelling variations:
thieu nang » thien nang, thieu khang, thieu quang
va trinh » van trinh, va tinh, lap trinh
trinh le » trinh ly, thinh le, trinh he
vu sach » vu bach, su sach, vu khach
so sanh » do sanh
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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 (so sanh)) thieu nang cao hoi. hieu va cac duc va trinh le ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sanh)) thieu nang cao hoi. hieu va cac duc va trinh le ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (so sanh)) thieu nang cao hoi. hieu va cac duc va trinh le ((cua tre) OR (cua te))*".