Perhaps you should try some spelling variations:
khoanh khac » khoa khac
anh khoanh » anh khoa, anh hoang, anh thanh
khoa thong » hoa thong, thoai thong, pho thong
khac thong » khac thuong, khac trong, khap thong
thuy toan » huy toan, thuy than, thuat toan
khoa khoa » hoa khoa, khuan khoa, khoa hoc
sach hai » sach bai, sach han, sach ha
hai thuy » thai thuy, ha thuy, hai thu
sanh dai » sinh dai, sanh dan, vanh dai
dai truc » dai thuc, doan truc, dai trung
truc anh » truc nano, truc tinh, truc bach
tu sach » thu sach, su sach, te sach
so sanh » do sanh

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 hai thuy toan khoa khoa thong ) or ( so sanh dai truc anh khoanh khac thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach hai thuy toan khoa khoa thong ) OR ( so sanh dai truc anh khoanh khac thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach hai thuy toan khoa khoa thong ) or ( so sanh dai truc anh khoanh khac thong ))*.