Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
nghien quang » nguyen quang, nghiep quan, nghe quang
nghiep toan » nghiep thanh, nghiep luan, nghiep tai
can trinh » can tranh, dan trinh, van trinh
quang hoc » quang hoi, quang huy, dung hoc
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
tu can » tu ban, tu cac, thu canh

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) OR (thu sach)) doanh nghiep toan khoa ) or ( tu can trinh nghien quang hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu sach) OR (thu sach)) doanh nghiep toan khoa ) OR ( tu can trinh nghien quang hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu sach) OR (thu sach)) doanh nghiep toan khoa ) or ( tu can trinh nghien quang hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( ((tu sach) OR (thu sach)) doanh nghiep toan khoa ) or ( tu can trinh nghien quang hoc ))*.