Perhaps you should try some spelling variations:
pham duy » pham duc
so sach » so sanh, bo sach, co sach
sach tu » sach thu, cach tu, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu su » hieu sau, tieu su, hieu so
su pham » san pham
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
va chua » vua chua, ca chua, va chu
chua te » cua te, chua tu, chua xe
duy va » duy vat, duy van, day va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tu ((nang xa) or (lang xa)) hoi. hieu su pham duy va tinh va chua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tu ((nang xa) OR (lang xa)) hoi. hieu su pham duy va tinh va chua te.
• Adding a wildcard symbol may retrieve word variants: so sach tu ((nang xa) or (lang xa)) hoi. hieu su pham duy va tinh va chua te*.