# To convert to 2-up format: need print/psutils-a4 package
psnup -nup 2 -pa4 freebsdref1.ps >freebsdref2.ps

# To convert postscript to pdf: need print/ghostscript-{gnu|apfl}
ps2pdf -sPAPERSIZE=a4 freebsdref1.ps
ps2pdf -sPAPERSIZE=a4 freebsdref2.ps