Perhaps you should try some spelling variations:
khoan khau » khoanh khac, khoa kham, khoa phau
khap thong » phap thong, khac thuong, chap thuong
khau thong » khau thuong, khau tong, khac thuong
khoi khap » hoi nhap, kho khan, khoa kham
toc sach » hoc sach, doc sach, thuoc sach
sach bai » sach dao, cac bai, sach xa
bai thuc » bai thuoc, bao thuc, dai thuc
thuc cac » thuc cach, tuc cac, phuc cac
cac khoi » cac thoi, cach thoi, hoc khoi
sach tri » sach tai, sach tren, sach truc
tri thuc » tri tue
bo sach » co sach, hoc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc sach bai thuc cac khoi khap thong ) or ( bo sach tri thuc cac khoan khau thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach bai thuc cac khoi khap thong ) OR ( bo sach tri thuc cac khoan khau thong ))*.