Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
thuoc sach » hoc sach, nuoc sach, thuat sach
trien chi » trien thi, trien khai, trieu thi
chi khoa » nhi khoa, chua khoa, thai khoa
khoa hoc » hoa hoc
phoi hoc » hoi hoc, phoi thuoc, hoa hoc
te sach » toc sach
xa phan » va phan, a phan, xuat phan
x phan » d phan, a phan, c phan

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 trien chi khoa hoc ) or ( thuoc sach ((xa phan) OR (x phan)) phoi hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach trien chi khoa hoc ) OR ( thuoc sach ((xa phan) OR (x phan)) phoi hoc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sach trien chi khoa hoc ) or ( thuoc sach ((xa phan) OR (x phan)) phoi hoc ))*".