Perhaps you should try some spelling variations:
sach pham » sach tham, sach phat, sach phap
pham thuc » phap thuc, pham chuc, nham thuc
hanh khoa » hang khoa, anh khoa, hanh hoa
hoc trong » hoc thuong, hoc tieng, dot trong
hoach dai » hoach dat, hoc dai, hoa dai
thuc cach » thuoc sach, truoc cach, tuc cac
cach hoan » cac khoan, hach toan, sach han
hoc sach » hoc sinh, hoc cac, hoc anh
khoa hoc » hoa hoc
dai thuc » dan thuc, dai thu, dai thua
hoan he » hoa he, toan he, hoan thue

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( hoc sach pham thuc hanh khoa hoc trong ) or ( thu hoach dai thuc cach hoan he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc sach pham thuc hanh khoa hoc trong ) OR ( thu hoach dai thuc cach hoan he thong )).
• Adding a wildcard symbol may retrieve word variants: (( hoc sach pham thuc hanh khoa hoc trong ) or ( thu hoach dai thuc cach hoan he thong ))*.