Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh nghe » trinh nghien, trinh he, trinh nha
tranh thai » trang thai, tran thi, tinh thai
tranh thi » tran thi, trinh thi, trang thai
tu hanh » du hanh, lu hanh, thuc hanh
nghe di » nghe vi, nghe dien, nghe dan
tu canh » thu canh, tu chanh, tu can
diu hoc » du hoc, dia hoc, lieu hoc
di hoc » dai hoc, dia hoc, li 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 di hoc ) or ( tu canh ((tranh thi) OR (tranh thai)) diu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hanh trinh nghe di hoc ) OR ( tu canh ((tranh thi) OR (tranh thai)) diu hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu hanh trinh nghe di hoc ) or ( tu canh ((tranh thi) OR (tranh thai)) diu hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( tu hanh trinh nghe di hoc ) or ( tu canh ((tranh thi) OR (tranh thai)) diu hoc ))*.