Perhaps you should try some spelling variations:
ha nghiem » khao nghiem, thi nghiem, thu nghiem
hoach ha » hoach va, hoach xay, hoach hoi
dao nghe » day nghe, da nghe, dat nghe
tu lanh » tu hanh, tu lenh, tu manh
nghe d » nghe di, nghe _, nghe 新
su hoa » su hoan, su hoat, su khoa
tu hoc » te hoc
d hoc » du hoc, ad hoc, de hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu lanh dao nghe d hoc ) or ( thu hoach ha nghiem ((su hoa) or (tu hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu lanh dao nghe d hoc ) OR ( thu hoach ha nghiem ((su hoa) OR (tu hoc)) )).
• Adding a wildcard symbol may retrieve word variants: (( tu lanh dao nghe d hoc ) or ( thu hoach ha nghiem ((su hoa) or (tu hoc)) ))*.