Perhaps you should try some spelling variations:
phuong trinh » chuong trinh, cong trinh, huong tran
tren phuong » trien phuong, tran phuong, ren phuong
trinh khoa » trinh hoa, sinh khoa, trinh hoi
phau thong » phap thong, khau thong, phan thong
than thong » than thuong, toan thong, tran thong
sach tren » sach tien, sach tranh
khoa phau » hoa phan, khoa kham, khoa thu
khoa than » khoa luan, hoa thai, hoa tan
sach tin » sach tien, sach kinh, sach han
bai khoa » tai khoa, dai khoa, mai khoa
so sach » so sanh, bo sach, co sach
tu sach » thu sach, su sach, te sach
tin hoc » sinh hoc
hoc bai » hoc dai, hoc giai

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 tren phuong trinh khoa phau thong ) or ( tu sach tin hoc bai khoa than thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sach tren phuong trinh khoa phau thong ) OR ( tu sach tin hoc bai khoa than thong )).
• Adding a wildcard symbol may retrieve word variants: (( so sach tren phuong trinh khoa phau thong ) or ( tu sach tin hoc bai khoa than thong ))*.