Perhaps you should try some spelling variations:
doanh khoa » toan khoa
phap thong » phap phong, phap chong, pho thong
sach tham » sach nha
dac doanh » cac doanh, dao doanh, van doanh
khau tong » khau thong, khau cong, khau thuong
thu sach » tu sach, thuat sach, thuoc sach
tham dac » pham dac, thai dac, tham dam

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach tham dac doanh khoa ((khau tong) OR (phap thong))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach tham dac doanh khoa ((khau tong) OR (phap thong))".
• Adding a wildcard symbol may retrieve word variants: thu sach tham dac doanh khoa ((khau tong) OR (phap thong))*.