Fix #42 (#45)

Closes #42

Author: jorgensd

chapter1/fundamentals_code.ipynb

@@ -264,7 +264,7 @@
     "## Forming and solving the linear system\n",
     "\n",
     "Having defined the finite element variational problem and boundary condition, we can create our `dolfinx.fem.LinearProblem`, as class for solving \n",
-    "the variational problem: Find $u_h\\in V$ such that $a(u_h, v)==L(v) \\quad \\forall v \\in \\hat{V}$. We will use PETSc as our linear algebra backend, using a direct solver (LU-factorization).  See the [PETSc-documentation](https://www.mcs.anl.gov/petsc/petsc-current/docs/linearsolvertable.html) of the method for more information."
+    "the variational problem: Find $u_h\\in V$ such that $a(u_h, v)==L(v) \\quad \\forall v \\in \\hat{V}$. We will use PETSc as our linear algebra backend, using a direct solver (LU-factorization).  See the [PETSc-documentation](https://petsc.org/main/docs/manual/ksp/?highlight=ksp#ksp-linear-system-solvers) of the method for more information."
    ]
   },
   {