Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
sach khong » sach thuong, sach song, bach khang
hoach dai » hoach dat, hoc dai, hoa dai
thuc cach » truoc cach, thuc hanh, tuc cac
cach khoa » bach khoa, cac khoa, cac khoan
khoa than » khoa luan, hoa thai, hoa tan
than tong » than trong, han tong, phan tong
dai thuc » dan thuc, dai thu, dai thua
na thuoc » nha thuoc, nam thuoc, va thuoc
khong he » khong khi, hong ha, khong _
cac na » cac nha, cac ba, cac nu
thong » trong

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 dai thuc cach khoa than tong ) or ( tu cac na thuoc sach khong he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu hoach dai thuc cach khoa than tong ) OR ( tu cac na thuoc sach khong he thong )).
• Adding a wildcard symbol may retrieve word variants: (( thu hoach dai thuc cach khoa than tong ) or ( tu cac na thuoc sach khong he thong ))*.