We are glad to inform you that the 25th number of the ISSI Newsletter has come out.

Content:

• Editorial
• Conference call: 16th Nordic Workshop
• News: Manfred Bonitz 80 – A Festschrift 
• News: Awardee of the Price Medal in 2011
• Olle Persson: Price-Award Mapping
• Ronald Rousseau & Fred Y. Ye: Subgraphs derived from the Hirsch core in undirected, unweighted networks
• Ronald Rousseau & Loet Leydesdorff: Simple arithmetic versus intuitive understanding
• Divya Srivastava & Rajni Kant: Directory & Database
• Wolfgang Glänzel: How to obtain Erdős number 1 in the 21th century?