SNF classes are located in archive px_8.zip

In order to obtain matrices contained in some SNF class,
first locate the corresponding file nnnx using table snfs.8,
and then issue the command
unpack nnn.
Result is the file nnn.x, containing one $\phi$-representative
in each row. The format is obvious: 8 pairs of hexadecimal digits
represent 8 rows of a matrix.