Perhaps you should try some spelling variations:
sanh tri » thanh tri, dinh tri, minh tri
tue cach » tu cach, thuc cach, ve cach
cach hoc » cach thuc, cach thoi, dich hoc
so sanh » do sanh
so sach » bo sach, co sach, hoc sach
tri thi » tai thi, thi thi, tri chi
tri tai » trinh tai
bach va » bach van, bach ha, sach va
hoc he » hoc hien
va he » va che, va ghe, va de

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sanh tri tue cach hoc he thong ) or ( so sach ((tri thi) OR (tri tai)) bach va he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh tri tue cach hoc he thong ) OR ( so sach ((tri thi) OR (tri tai)) bach va he thong )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so sanh tri tue cach hoc he thong ) or ( so sach ((tri thi) OR (tri tai)) bach va he thong ))".
• Adding a wildcard symbol may retrieve word variants: (( so sanh tri tue cach hoc he thong ) or ( so sach ((tri thi) OR (tri tai)) bach va he thong ))*.