Perhaps you should try some spelling variations:
he trong » he thong, he trung, le trong
sanh tri » thanh tri, dinh tri, minh tri
thi hanh » thi thanh
sach tri » sach tai, sach tren, sach truc
hanh ha » nhanh ha, thanh ha, hanh hoa
tri thi » tri tai, tai thi, thi thi
bo sach » co sach, hoc sach
so sanh » do sanh
va cach » va cac
ve cach » ve cac, ve canh
ha he » ha le, va he

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 ((ve cach) OR (va cach)) hoa he trong ) or ( bo sach tri thi hanh ha he trong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh tri ((ve cach) OR (va cach)) hoa he trong ) OR ( bo sach tri thi hanh ha he trong )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so sanh tri ((ve cach) OR (va cach)) hoa he trong ) or ( bo sach tri thi hanh ha he trong ))".
• Adding a wildcard symbol may retrieve word variants: (( so sanh tri ((ve cach) OR (va cach)) hoa he trong ) or ( bo sach tri thi hanh ha he trong ))*.