In August 1904, leaders of the socialist parties from around the world gathered in Amsterdam for the Sixth Congress of the Socialist International. <a rel="nofollow" class="external free" href="https://rosaluxemburgblog.wordpress.com/2012/07/03/think-you-know-your-leaders-of-the-second-international/">https://rosaluxemburgblog.wordpress.com/2012/07/03/think-you-know-your-leaders-of-the-second-international/</a>
Leenheer, Cornelius
between circa 14 August 1904 and circa 20 August 1904 <div style="display: none;">date QS:P,+1904-08-00T00:00:00Z/10,P1319,+1904-08-14T00:00:00Z/11,P1326,+1904-08-20T00:00:00Z/11,P1480,Q5727902</div>
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