Perhaps you should try some spelling variations:
khoanh khac » khoa khac
cac khoanh » cac khoan, cac thanh, cac doanh
khan thong » khap thong, khau thong, nhan thong
khac thong » khac thuong, khac trong, khap thong
thuc cach » thuoc sach, truoc cach, thuc hanh
sach truc » cach thuc, sach tren, sach thu
cach tri » cach thoi, cac tro, cach noi
tri thuc » tri tue
pha khan » pham khanh, phap khang, phap phan
thu sach » tu sach, thuat sach, thuoc sach
truc tac » truc tai, truc bach, truc giac
tu cach » tu cac
tac cac » thac cac, tai cac, tap cac

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

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