ENDURO-SENIOREN DEUTSCHLAND
(Enduro Seniors of Germany)
This site is in German, but Leo Keller tells me he is making an English version. The English version is up and running

GREEVES INTERNATIONAL
An article on ISDT Greeves Motorcycles.

JAWA ISDT/ISDE MOTORCYCLE
Jawa ISDT/E motorcycle development article on the CZECHPOINT (Jawa, CZ, ESO and other Czech motorcycles)  web page.