Perhaps you should try some spelling variations:
thoi nghiem » thi nghiem, khoi nghiep, thuc nghiem
thuoc cach » thuoc sach, thuc cach, truoc cach
cach thoi » cac thoi, cach thuc, cach noi
dao nghe » day nghe, dat nghe, nao nghe
tu lanh » tu hanh, tu lenh, tu manh
da nghe » day nghe, va nghe, dang nghe
tu hoc » te hoc
d hoc » du hoc, ad hoc, de hoc
su ho » su hoa, su hoc, su pho

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) OR (da nghe)) d hoc ) or ( thuoc cach thoi nghiem ((su ho) or (tu hoc)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu lanh ((dao nghe) OR (da nghe)) d hoc ) OR ( thuoc cach thoi nghiem ((su ho) OR (tu hoc)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu lanh ((dao nghe) OR (da nghe)) d hoc ) or ( thuoc cach thoi nghiem ((su ho) or (tu hoc)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tu lanh ((dao nghe) OR (da nghe)) d hoc ) or ( thuoc cach thoi nghiem ((su ho) or (tu hoc)) ))*.