Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
sach trinh » sach tranh, hanh trinh, sach kinh
sach trac » sach truc, sach tranh, sach tham
nghiem am » nghiem lam, nghiem ban, nghiem van
hoc sach » hoc sinh, hoc cac, hoc anh
thiet bi » thiet ke
te sach » toc sach
bi hoc » bai hoc, li hoc, vi hoc
am hoc » ad hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( hoc sach trinh thiet bi hoc ) or ( te sach trac nghiem am hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc sach trinh thiet bi hoc ) OR ( te sach trac nghiem am hoc )).
• Adding a wildcard symbol may retrieve word variants: (( hoc sach trinh thiet bi hoc ) or ( te sach trac nghiem am hoc ))*.