Perhaps you should try some spelling variations:
than thong » than thuong, toan thong, tran thong
sach tham » sach nha
tham thuc » nham thuc, pham thuc, tam thuc
hanh khoa » hang khoa, anh khoa, hanh hoa
chuc danh » chuc nganh, chuc nang, thuc dan
danh khoa » doanh khoa, anh khoa, danh hoa
khoa than » khoa luan, hoa thai, hoa tan
sach bai » sach dao, cac bai, sach xa
bai chuc » bai thuoc, tai cuc, bai hoc
tu sach » thu sach, su sach, tu cach
khoa he » hoa he, khoa hoc, khong he
te sach » toc sach

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

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