Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hanh tich » hanh thich, thanh tich, hanh tinh
trinh dau » trinh cau, trinh da, trinh dan
toan giao » ton giao, toan cao, hoa giao
don gian » dan gian
tich so » tich bao, tinh son
lu hanh » luu hanh, du hanh, ly hanh
thuc » thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thuc hanh tich so - don gian ) or ( lu hanh trinh dau - toan giao ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuc hanh tich so - don gian ) OR ( lu hanh trinh dau - toan giao )).
• Adding a wildcard symbol may retrieve word variants: (( thuc hanh tich so - don gian ) or ( lu hanh trinh dau - toan giao ))*.