Perhaps you should try some spelling variations:
trinh chao » trinh han, trinh co, trinh giao
trinh chat » tinh chat, trinh luat, trinh han
canh trinh » canh tranh, hanh trinh, canh tinh
trinh nghe » trinh nghien, trinh he, trinh nha
nghe dien » nghe tieng, nghe dan, nghe hieu
thu sach » tu sach, thuat sach, thuoc sach
dien hoc » dien hoa, khien hoc, tin hoc
tu canh » thu canh, tu chanh, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu sach ((trinh chao) OR (trinh chat)) li hoc ) or ( tu canh trinh nghe dien hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu sach ((trinh chao) OR (trinh chat)) li hoc ) OR ( tu canh trinh nghe dien hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thu sach ((trinh chao) OR (trinh chat)) li hoc ) or ( tu canh trinh nghe dien hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( thu sach ((trinh chao) OR (trinh chat)) li hoc ) or ( tu canh trinh nghe dien hoc ))*.