Perhaps you should try some spelling variations:
sach nang » cach mang, sach dung, sach danh
nang thuc » dang thuoc, nhanh thuc, trang thuc
hanh khoa » hang khoa, anh khoa, hanh hoa
sach thai » sach tham, sac thai, sach tai
thai thuc » thai thuy, thai tuc, tham thuc
thuc cac » thuc cach, tuc cac, phuc cac
khoan he » khoan ke, khoan le, khoan hoi
te sach » toc sach
khoa he » hoa he, khoa hoc, khong he

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te sach nang thuc hanh khoa he thong ) or ( te sach thai thuc cac khoan he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach nang thuc hanh khoa he thong ) OR ( te sach thai thuc cac khoan he thong )).
• Adding a wildcard symbol may retrieve word variants: (( te sach nang thuc hanh khoa he thong ) or ( te sach thai thuc cac khoan he thong ))*.