Perhaps you should try some spelling variations:
khoan phai » khong phai, khoa phau, khoan nhoi
bach khoan » bach khoa, bach hoa, bach khang
phai thong » phap thong, phai tuong, phan thong
sach tham » sach nha
tham thuc » nham thuc, pham thuc, tam thuc
khoan hoi » khoan nhoi, khoa hoi, khoa hoc
hoi thong » hoi thuong, hoi trong, hoa thong
toan tran » thoan tran, tan tran, hoan tran
tran thuc » trang thuc, toan thuc, tran thuy
thuc bach » truc bach, thuc cach, thuoc sach
thuc cac » thuc cach, tuc cac, phuc cac
tu sach » thu sach, su sach, te sach

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 tham thuc cac khoan hoi thong ) or ( thuat toan tran thuc bach khoan phai thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tham thuc cac khoan hoi thong ) OR ( thuat toan tran thuc bach khoan phai thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tham thuc cac khoan hoi thong ) or ( thuat toan tran thuc bach khoan phai thong ))*.