Perhaps you should try some spelling variations:
tuan doanh » toan doanh, nhuan doanh, tuan anh
doanh khoa » toan khoa
hoi phong » hai phong, voi phong, doi phong
phai sinh » phau sinh, thai binh, pham minh
sinh khoa » sinh hoc, sinh hoat, anh khoa
sach tri » sach tai, sach tren, sach truc
tri tuan » tri quan, tran tuan, tri tue
khoa hoi » khoan hoi, khoa hoc, khoa doi
sanh khi » sinh khoi, manh khai, san chi
khi phai » khi thai, chi phi, khi hau
khoa han » khoa than, hoa han, khoa can
tu sach » thu sach, su sach, te sach
so sanh » do sanh
tong » cong, dong, song

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach tri tuan doanh khoa hoi phong ) or ( so sanh khi phai sinh khoa han tong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tri tuan doanh khoa hoi phong ) OR ( so sanh khi phai sinh khoa han tong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tri tuan doanh khoa hoi phong ) or ( so sanh khi phai sinh khoa han tong ))*.