Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh nghe » trinh nghien, trinh he, trinh nha
canh trinh » canh tranh, canh tinh, anh trinh
trinh thi » trinh tai, dinh thi, trinh tu
tu hanh » du hanh, lu hanh, thuc hanh
nghe li » nghe vi, nghe di, nghe ki
tu canh » thu canh, tu chanh, tu can
thi dia » thi dua, thi da, thi diu
dia hoc » dia oc, dich hoc, dien hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu hanh trinh nghe li hoc ) or ( tu canh trinh thi dia hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hanh trinh nghe li hoc ) OR ( tu canh trinh thi dia hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu hanh trinh nghe li hoc ) or ( tu canh trinh thi dia hoc ))*.