Perhaps you should try some spelling variations:
sach trinh » sach tranh, sach kinh, sach tren
hanh trinh » canh tranh, hanh chinh
thi nghiem » thuc nghiem
nghiem ad » nghiem d, nghiem ban, nghiem lam
sach thi » sach thu, sach tai, sach thieu
te sach » toc sach
vat d » vat da, vat de, vat _
d hoc » du hoc, de hoc, y 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) or (hanh trinh)) vat d hoc ) or ( te sach thi nghiem ad hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc ((sach trinh) OR (hanh trinh)) vat d hoc ) OR ( te sach thi nghiem ad hoc )).
• Adding a wildcard symbol may retrieve word variants: (( hoc ((sach trinh) or (hanh trinh)) vat d hoc ) or ( te sach thi nghiem ad hoc ))*.