On 2017-03-21, Robert South wrote:

>  From the Sona book linked to from your website (2nd link, the first is
> broken, also thanks for all that I'll take a serious look at Sona):
> [...]

I don't know why the first link seems broken. It works perfectly well 
for me (Firefox 52.0.1 (32-bit) Windows 7 Professional). The second link 
just maps to the first link and is an alternative because some mobile 
devices cannot (or cannot easily) enter the tilde character ~.

>>          I have numerous materials on Sona (including a printable scan
>> of "The Book") in my personal webspace at
>> also available for mobile devices as
>> .

Paul Bartlett