Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
thieu nghiem » thi nghiem, thu nghiem, thieu nhi
nghiem duoc » nghiem thuoc, nghe duoc
sach trinh » sach tranh, hanh trinh, sach kinh
duoc hoc » quoc hoi
nghien d » nghiem d, nghien o, nghiem de
su sach » so sach
vu sach » vu bach, vu khach
d hoc » du hoc, ad hoc, de hoc

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 thieu nghiem duoc hoc ) or ( vu sach trinh nghien d hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach thieu nghiem duoc hoc ) OR ( vu sach trinh nghien d hoc )).
• Adding a wildcard symbol may retrieve word variants: (( su sach thieu nghiem duoc hoc ) or ( vu sach trinh nghien d hoc ))*.