Unfortunately it is removed, not really nice.
But ok, as convbsd wrote, take it from debian snapshots.
for x64
wget -c http://snapshot.debian.org/archive/debian/20141021T164213Z/pool/main/d/dpkg/dpkg_1.17.18_amd64.deb. && dpkg -i dpkg_1.17.18_amd64.deb && apt-mark hold dpkg
for i386
wget -c http://snapshot.debian.org/archive/debian/20141021T164213Z/pool/main/d/dpkg/dpkg_1.17.18_i386.deb. && dpkg -i dpkg_1.17.18_i386.deb && apt-mark hold dpkg