Perhaps you should try some spelling variations:
trinh nghiep » trinh nghien, trinh nghe, trinh ghep
hanh trinh » canh tranh, hanh chinh
sach trach » sach tranh, sach truc
nghiep ke » nghiep che, nghiep va, nghiep vu
nhiem dan » nghiem ban, nghiem van, nghiem dau
lu hanh » luu hanh, du hanh, ly hanh
dan hoc » van hoc, dan toc, dai hoc
ke hoc » te hoc, de hoc, ke ho

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 nghiep ke hoc ) or ( thuoc ((sach trach) or (sat trach)) nhiem dan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( lu hanh trinh nghiep ke hoc ) OR ( thuoc ((sach trach) OR (sat trach)) nhiem dan hoc )).
• Adding a wildcard symbol may retrieve word variants: (( lu hanh trinh nghiep ke hoc ) or ( thuoc ((sach trach) or (sat trach)) nhiem dan hoc ))*.