Perhaps you should try some spelling variations:
cong thuoc » cong thuc, dong thuoc, long thuoc
thuoc dang » thuoc dung, thuoc khang, thuc dan
cong quang » luong quang, thong quang, duong quang
quang phan » quang chan, quang phat, quang thanh
dang cong » dung cong
ho chieu » theo chieu, hoc thieu, mot chieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) OR (toc thieu)) sach - thanh cong thuoc dang cong quang phan tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (toc thieu)) sach - thanh cong thuoc dang cong quang phan tu".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (toc thieu)) sach - thanh cong thuoc dang cong quang phan tu*.