Perhaps you should try some spelling variations:
sach tranh » canh tranh
sach danh » sach dao, sach dung, sach kinh
kxy thuat » ky thuat, ki thuat, ky thua
thuat do » thuat o
my thuat » ky thuat, ki thuat, va thuat
tu sach » thu sach, su sach, te sach
y thuat » ky thuat, ki thuat, va thuat
danh y » anh y, hanh y, dan y
do hoc » co hoc, do hoa, du 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 sach danh y thuat do hoc ) or ( tu sach tranh ((kxy thuat) OR (my thuat)) hoa hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach danh y thuat do hoc ) OR ( tu sach tranh ((kxy thuat) OR (my thuat)) hoa hoc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach danh y thuat do hoc ) or ( tu sach tranh ((kxy thuat) OR (my thuat)) hoa hoc ))*".