update http get spec reference for #503

src/world-interactions.html

@@ -216,10 +216,10 @@ <h3 id="world-int-transfers">Transferring MathML</h3>
   the available formats; a potential recipient accepts or rejects a drop
   based on the list of available formats, and the drop action allows the
   receiving application to request the delivery of the data in one of the
-  indicated formats.  An HTTP GET transfer, as in [[HTTP11]],
+  indicated formats.  An HTTP GET transfer, as in [[rfc9110]],
   allows a client to submit a list of acceptable media types; the server
   then delivers the data using one of the indicated media types.
-  An HTTP POST transfer, as in [[HTTP11]], allows a client
+  An HTTP POST transfer, as in [[rfc9110]], allows a client
   to submit data labelled with a media type that is acceptable to the
   server application.</p>