Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh thuc » trinh thuc, trang thuc, thanh thuy
khan thong » khap thong, khau thong, nhan thong
toan trinh » thanh trinh, trang trinh, toan tin
bach khoa » anh khoa
pho thong » he thong
thu sach » tu sach, thuat sach, thuoc sach
hanh kho » hanh khu, hang khoa, hanh theo
kho khan » khoa kham, khoa than
trinh tu » trinh ky, trinh do
khoa pho » khoa phu, khoa khoa, khoa phau
tu bach » vu bach, tu cach, tu bac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu sach tranh thuc hanh kho khan thong ) or ( thuat toan trinh tu bach khoa pho thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach tranh thuc hanh kho khan thong ) OR ( thuat toan trinh tu bach khoa pho thong )).
• Adding a wildcard symbol may retrieve word variants: (( thu sach tranh thuc hanh kho khan thong ) or ( thuat toan trinh tu bach khoa pho thong ))*.