Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
sach trinh » sach tranh, hanh trinh, sach kinh
nghien ban » nghiem ban, nghiep ban, nghiep bang
nghiem de » nghiem do, nghiem te, nghiem ve
sach tai » sach bai, sach tham, sach dao
nghiem d » nghiem do, nghiem _, nghiem h
tu sach » thu sach, su sach, te sach
so sach » so sanh, bo sach, co sach
ban hoa » van hoa, ba hoa, bao hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach tai ((nghiem de) or (nghiem d)) ho ) or ( so sach trinh nghien ban hoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tai ((nghiem de) OR (nghiem d)) ho ) OR ( so sach trinh nghien ban hoa )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tai ((nghiem de) or (nghiem d)) ho ) or ( so sach trinh nghien ban hoa ))*.