Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
nghien dien » nghiep dien, nghe dien, khien dien
hanh trinh » canh tranh, hanh chinh
sach tranh » canh tranh
nghiem de » nghiem te, nghiem ve, nghiem dau
dien hoc » dien hoa, khien hoc, tin hoc
thu sach » tu sach, thuat sach, thuoc sach
nghiem d » nghiem _, nghiem h, nghiem y
tu hanh » du hanh, lu hanh, thuc hanh

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 nghien dien hoc ) or ( thu sach tranh ((nghiem de) or (nghiem d)) hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hanh trinh nghien dien hoc ) OR ( thu sach tranh ((nghiem de) OR (nghiem d)) hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu hanh trinh nghien dien hoc ) or ( thu sach tranh ((nghiem de) or (nghiem d)) hoc ))*.