private void WcfCrmClientOnCrmServerCallHistoryEntryAdded(object sender, CallHistoryEntry callHistoryEntry) { lock (_lockObj) { var affectedEntries = _internalCrmEntries.Where(entry => entry.PhoneNumber.Equals(callHistoryEntry.Callee) || entry.PhoneNumber.Equals(callHistoryEntry.Caller)); foreach (var affectedEntry in affectedEntries) { affectedEntry.CallHistoryEntries.Add(callHistoryEntry); } } RaisePropertyChanged("CrmEntries"); }