Perhaps you should try some spelling variations:
khoanh khac » khoa khac
cac khoanh » cac khoan, cac thanh, cac doanh
khac trong » khac thuong, hoc trong, tac trong
khan thong » khap thong, khau thong, nhan thong
thuc cach » thuoc sach, truoc cach, thuc hanh
sach bai » sach dao, cac bai, sach xa
bai thuc » bai thuoc, bao thuc, dai thuc
thuc cac » tuc cac, phuc cac, thac cac
thu sach » tu sach, thuat sach, thuoc sach
sach tri » sach tai, sach tren, sach truc
tri thuc » tri tue
cach kho » bach khoa, cach thoi, cach pha
kho khan » khoa kham, khoa than
su sach » so sach, vu sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach bai thuc cac khoanh khac trong ) or ( thu sach tri thuc cach kho khan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach bai thuc cac khoanh khac trong ) OR ( thu sach tri thuc cach kho khan thong )).
• Adding a wildcard symbol may retrieve word variants: (( su sach bai thuc cac khoanh khac trong ) or ( thu sach tri thuc cach kho khan thong ))*.