The new manual  ‘Dialog Tandem: Conflict prevention and solution by language exchange’ (4th version) can be downloaded as pdf here free of charge . The mobi and epub versions are available here, using the address ‘network@tandem-f.org‘ and the password ‘password18‘.
If you want twice per year information about the progress, please send Name + Institution + ‘PT mailing’ to contact (at) tandemcity.info.

You can also use the manual (from chapter 5) as a general tandem manual.