Perhaps you should try some spelling variations:
trinh nghe » trinh nghien, trinh he, trinh nha
hanh trinh » canh tranh, hanh chinh
nghiem tu » nghiep tu, nghiem te, nghiem xu
nghiem su » nghiem xu, nghiem ngu, nghiem dau
duy hanh » duy khanh, duy nhanh, du hanh
su sach » so sach, vu sach
nghe su » nghe sua, nghe xu, nghe so
su hoc » tu hoc, du hoc, so hoc
kinh » dinh, minh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach kinh ((nghiem tu) or (nghiem su)) hoc ) or ( duy hanh trinh nghe su hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach kinh ((nghiem tu) OR (nghiem su)) hoc ) OR ( duy hanh trinh nghe su hoc )).
• Adding a wildcard symbol may retrieve word variants: (( su sach kinh ((nghiem tu) or (nghiem su)) hoc ) or ( duy hanh trinh nghe su hoc ))*.