 These instructions stated that the objectives of the Partisans meant that there could be no cooperation between them and the Chetniks . They also appointed Đurišić as a Chetnik vojvoda . Some historians have challenged the authenticity of these instructions ; they say the document was a forgery made by Đurišić after he failed to reach Mihailović . Other historians either do not mention any controversy about the provenance of the instructions , mention evidence supporting their authenticity , or explicitly state they consider them to be authentic . 
