Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
pham duy » pham duc
sach tu » sach thu, cach tu, sach uu
hieu ve » hieu va, hieu van
nang ho » nang hoc, nang co, tang ho
sach ty » sach y, sach thu, xach tay
ve pham » vi pham, v pham, ve phan
ho hoi » hoc hoi, hoa hoi, hoi hoi
duy va » duy vat, duy van, day va
di su » doi su, da su, de su
ki su » ky su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tu) OR (sach ty)) nang ho hoi. hieu ve pham duy va thanh ((di su) OR (ki su)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tu) OR (sach ty)) nang ho hoi. hieu ve pham duy va thanh ((di su) or (ki su)) triet~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tu) OR (sach ty)) nang ho hoi. hieu ve pham duy va thanh ((di su) or (ki su)) triet*.