Removes non-existing links

Author: anenadic

_extras/persistence.md

@@ -25,7 +25,7 @@ keypoints:
 
 > ## Follow up from Section 3
 > This episode could be read as a follow up from the end of
-> [Section 3 on software design and development](../35-refactoring-architecture/index.html#conclusion).
+> [Section 3 on software design and development](../35-software-architecture-revisited/index.html#towards-collaborative-software-development).
 {: .callout}
 
 Our patient data system so far can read in some data, process it, and display it to people.
@@ -354,9 +354,7 @@ class PatientSerializer(Serializer):
 > We've now got some code which we can use to save and load our patient data,
 > but we've not yet linked it up so people can use it.
 >
-> Just like we did with the `display_patient` view in
-> [Section 3](../36-architecture-revisited/index.html#mvc-revisited),
-> try adding some views to work with our patient data using the JSON serialiser.
+> Try adding some views to work with our patient data using the JSON serialiser.
 > When you do this, think about the design of the command line interface -
 > what arguments will you need to get from the user,
 > what output should they receive back?