Perhaps you should try some spelling variations:
tranh nhiem » trach nhiem, trinh nhiet
sach tranh » canh tranh
xi nghiep » su nghiep
nghiep te » nghiep ke, nghiep tu, nghiem te
khang xi » khang vi, khang voi, zhang xin
thu sach » tu sach, thuat sach, thuoc sach
tin hoc » sinh hoc
du hoc » tu hoc, duoc hoc
thuoc » thuc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thuoc khang xi nghiep te hoc ) or ( thu sach tranh nhiem ((du hoc) or (tin hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuoc khang xi nghiep te hoc ) OR ( thu sach tranh nhiem ((du hoc) OR (tin hoc)) )).
• Adding a wildcard symbol may retrieve word variants: (( thuoc khang xi nghiep te hoc ) or ( thu sach tranh nhiem ((du hoc) or (tin hoc)) ))*.