Perhaps you should try some spelling variations:
pham duy » pham duc
su sach » so sach, vu sach
tu nang » tru nang, tu nano, tu lang
tu nong » tu dong, tu cong, tu tong
hieu vu » hieu va, hieu ve, hieu su
vu pham » su pham, vi pham, vu kham
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
duy va » duy vat, duy van, day va
che tu » che thuy

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 ((tu nang) or (tu nong)) xa hoi. hieu vu pham duy va tinh va che tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((tu nang) OR (tu nong)) xa hoi. hieu vu pham duy va tinh va che tu*.