Links for petsc

http://ftp.mcs.anl.gov/pub/petsc/release-snapshots/petsc-lite-3.3-p7.tar.gz#md5=2f5c3fa9cdf229388ba6eb26d31367ab#egg=petsc-3.3.7
http://ftp.mcs.anl.gov/pub/petsc/release-snapshots/petsc-lite-3.4.5.tar.gz#md5=9b454253e587aa95096d8a9df615ab09#egg=petsc-3.4.5
http://ftp.mcs.anl.gov/pub/petsc/release-snapshots/petsc-lite-3.5.1.tar.gz#md5=539b3bdb627407b7e4e9e830fd5ccf43#egg=petsc-3.5.1
http://ftp.mcs.anl.gov/pub/petsc/release-snapshots/petsc-lite-3.5.2.tar.gz#md5=d707336a98d7cb31d843804d020edc94#egg=petsc-3.5.2