Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuoc sinh
thuat sach » thuat lanh, thuat san
trinh cong » trinh dung
sach dao » lanh dao
cong khi » cong thai, khong khi, co khi
te sach » toc sach
dao cao » dao tao, bao cao, tao cao
cao khi » cao khai, co khi, cao thi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te sach dao cao khi đong luc ) or ( ((thuoc sach) OR (thuat sach)) trinh cong khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach dao cao khi đong luc ) OR ( ((thuoc sach) OR (thuat sach)) trinh cong khi đong luc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sach dao cao khi đong luc ) or ( ((thuoc sach) OR (thuat sach)) trinh cong khi đong luc ))".
• Adding a wildcard symbol may retrieve word variants: (( te sach dao cao khi đong luc ) or ( ((thuoc sach) OR (thuat sach)) trinh cong khi đong luc ))*.