Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
hanh trinh » canh tranh, hanh chinh
thiet ban » thien ban, thien bang, thiet bi
nghiem va » nghiep va, nghiep vua, nghiep vu
lu hanh » luu hanh, du hanh, ly hanh
ban hoc » bang hoc, van hoc, bai hoc
su sach » vu sach
so sach » so sanh, bo sach, co sach
va hoc » van hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( lu hanh trinh thiet ban hoc ) or ( ((su sach) or (so sach)) trac nghiem va hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( lu hanh trinh thiet ban hoc ) OR ( ((su sach) OR (so sach)) trac nghiem va hoc )).
• Adding a wildcard symbol may retrieve word variants: (( lu hanh trinh thiet ban hoc ) or ( ((su sach) or (so sach)) trac nghiem va hoc ))*.