Perhaps you should try some spelling variations:
khanh thich » hanh thich, khanh trach, thanh tich
khanh thanh » nhanh thanh, thanh thanh, phan thanh
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hoc giao » hoc cao
thi hanh » thi thanh
don gian » dan gian
tinh so » tinh son, tinh soc, dinh so

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( duy ((khanh thich) OR (khanh thanh)) su - hoc giao ) or ( thi hanh tinh so - don gian ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( duy ((khanh thich) OR (khanh thanh)) su - hoc giao ) OR ( thi hanh tinh so - don gian ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( duy ((khanh thich) OR (khanh thanh)) su - hoc giao ) or ( thi hanh tinh so - don gian ))*".