Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh cong » trinh dung
sach tren » sach tranh
sach tien » sach thieu
hong thai » cong thai, hong ha, hinh thai
cong khi » cong thai, khong khi, co khi
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 cong khi đong luc ) or ( te ((sach tren) OR (sach tien)) hong thai đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hanh trinh cong khi đong luc ) OR ( te ((sach tren) OR (sach tien)) hong thai đong luc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu hanh trinh cong khi đong luc ) or ( te ((sach tren) OR (sach tien)) hong thai đong luc ))*".