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