Hacky fix for #989 (#1039)

Author: siwelwerd

publication/publication-619.ptx

@@ -106,7 +106,7 @@
     javascript, etc).  -->
     <calculator model="none" activecode="none" />
     <!-- Set the base URL of where the online version is hosted to have links in other formats -->
-    <baseurl href="https://tbil.org"/>
+    <baseurl href="https://library.tbil.org/2026/linear-algebra/"/>
     <!-- Control behavior of online WeBWorK, per type: -->
     <webwork
       inline="dynamic"