Perhaps you should try some spelling variations:
khan thong » khap thong, khau thong, nhan thong
thuc cach » thuoc sach, truoc cach, thuc hanh
phan tong » phan trong, phan cong, han tong
xay thuc » cay thuc, day thuc, xa thuc
cach hoc » cach thuc, cach thoi, dich hoc
hoc phan » hoc dan, hoc pho
sanh tai » sang tai, hanh tai, anh tai
hoc sach » hoc sinh, hoc cac, hoc anh
sach kho » bach khoa, sach dao, sach nha
kho khan » khoa kham, khoa than
so sanh » do sanh
tai hoc » thai hoc, dai hoc, bai hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu hoach xay thuc cach hoc phan tong ) or ( so sanh tai hoc sach kho khan thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu hoach xay thuc cach hoc phan tong ) OR ( so sanh tai hoc sach kho khan thong )).
• Adding a wildcard symbol may retrieve word variants: (( thu hoach xay thuc cach hoc phan tong ) or ( so sanh tai hoc sach kho khan thong ))*.