Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
trinh thi » trinh tai, dinh thi, trinh tu
trinh nha » trinh phan, trinh chat, trinh chao
nha dieu » nhan dieu, nhan dien, khoa dieu
dieu hoc » lieu hoc, dien hoc, dieu hoa
tu hanh » du hanh, thuc hanh, thi hanh
tu canh » thu canh, tu chanh, tu can
dia hoc » dia oc, dich hoc, dien hoc
lu hanh » luu hanh, du hanh, ly hanh
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: (( ((tu hanh) or (lu hanh)) trinh nha dieu hoc ) or ( tu canh trinh thi ((du hoc) or (dia hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((tu hanh) OR (lu hanh)) trinh nha dieu hoc ) OR ( tu canh trinh thi ((du hoc) OR (dia hoc)) )).
• Adding a wildcard symbol may retrieve word variants: (( ((tu hanh) or (lu hanh)) trinh nha dieu hoc ) or ( tu canh trinh thi ((du hoc) or (dia hoc)) ))*.