mention that additional copyright holders and licencing statements exist
diff --git a/LICENCE b/LICENCE
index aa72b32..f69d6c8 100644
--- a/LICENCE
+++ b/LICENCE
@@ -12,3 +12,7 @@
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+See the individual source code files for additional licence statements
+by other copyright holders.