Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
canh trinh » canh tranh, hanh trinh, canh tinh
thuoc sach » hoc sach, nuoc sach, thuoc sinh
thuat sach » thuat lanh, thuat san
nghe duoc » nghiem duoc, nghe nuoi, che duoc
thu canh » thuc hanh, thu cong, thu ban
thiet du » thiet de, thiet yeu, thiet ke
jin nghe » jin nghiem, gian nghe, tinh nghe
duoc hoc » quoc hoi
du hoc » tu hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( thu canh trinh thiet du hoc ) or ( ((thuoc sach) or (thuat sach)) jin nghe duoc hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu canh trinh thiet du hoc ) OR ( ((thuoc sach) OR (thuat sach)) jin nghe duoc hoc )).
• Adding a wildcard symbol may retrieve word variants: (( thu canh trinh thiet du hoc ) or ( ((thuoc sach) or (thuat sach)) jin nghe duoc hoc ))*.