Bob wrote:

Get a copy of RDH4, it superceeds RDH3 anyway. Though for your
semental reasons, a copy of RDH4 would be good to have a complete copy
of.

PDFs of RDH4 can be downloaded from
http://geek.scorpiorising.ca/RDH4.html

RDH3 - a very good simple intro. RDH4 is much tougher
going but much more complete, maybe a bit daunting for
a beginner.

Andy