Perhaps you should try some spelling variations:
phuong trinh » chuong trinh, cong trinh, huong tran
lang phuong » bang phuong, lan phuong, lang phong
han phuong » van phuong, dan phuong, han thuong
gian lang » gian dan
giai han » giai san, giai phap, giai phau
sach cha » sach che, sach ha, sach cua
te sach » toc sach
de giai » dan giai, kem giai
me gian » me giai, ma giang
nha de » nhat de, nha da, nha xe

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: (( te sach nha de giai han phuong trinh ) OR ( te sach cha me gian lang phuong trinh ))~.
• Adding a wildcard symbol may retrieve word variants: (( te sach nha de giai han phuong trinh ) or ( te sach cha me gian lang phuong trinh ))*.