Perhaps you should try some spelling variations:
tranh nghiep » doanh nghiep, trinh nghien, trinh nghe
thanh trinh » hanh trinh, thanh tinh, thanh binh
trinh thiet » trinh viet, trinh thi
thuoc sach » hoc sach, nuoc sach, thuat sach
ly thanh » le thanh, ly hanh, ly khanh
thiet du » thiet de, thiet yeu, thiet ke
dau hoc » dai hoc, dan hoc, day hoc
du hoc » tu hoc, duoc hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ly thanh trinh thiet du hoc ) or ( thuoc sach ((tranh nghiep) or (trac nghiem)) dau hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ly thanh trinh thiet du hoc ) OR ( thuoc sach ((tranh nghiep) OR (trac nghiem)) dau hoc )).
• Adding a wildcard symbol may retrieve word variants: (( ly thanh trinh thiet du hoc ) or ( thuoc sach ((tranh nghiep) or (trac nghiem)) dau hoc ))*.