# Dead link in documentation

**URL:** <https://igraph.discourse.group/t/dead-link-in-documentation/492>\
**Category:** Usage\
**Tags:** Python\
**Created:** [21 October 2020 22:33 UTC](https://igraph.discourse.group/t/dead-link-in-documentation/492 "2020-10-21T22:33:03Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![eduamf](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/eduamf/32/397_2.png) [@eduamf](https://igraph.discourse.group/u/eduamf)\
**Post date:** [21 October 2020 22:33 UTC](https://igraph.discourse.group/t/dead-link-in-documentation/492/1 "2020-10-21T22:33:03Z")

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Taking the opportunity, the link [Zachary karate club study](http://nexus.igraph.org/api/dataset?id=1&format=GraphML), in Documentation, is broken.

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**Author:** ![vtraag](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/vtraag/32/38_2.png) [@vtraag](https://igraph.discourse.group/u/vtraag)\
**Post date:** [22 October 2020 06:49 UTC](https://igraph.discourse.group/t/dead-link-in-documentation/492/2 "2020-10-22T06:49:55Z")

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Thanks for reporting this! Could you point us to the location of this link in the documentation? We will then correct it.

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**Author:** ![aristeidis](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@aristeidis](https://igraph.discourse.group/u/aristeidis)\
**Post date:** [20 September 2021 04:03 UTC](https://igraph.discourse.group/t/dead-link-in-documentation/492/3 "2021-09-20T04:03:59Z")

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In [igraph and the outside world](https://igraph.org/python/doc/tutorial/tutorial.html), both links referring to the **Zachary karate club study** and **igraph’s own graph repository called Nexus** are broken.

> As an exercise, download the graph representation of the well-known **Zachary karate club study** from igraph’s own graph repository called **[Nexus](http://nexus.igraph.org)**, unzip it and try to load it into _igraph_ .

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**Author:** ![szhorvat](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/szhorvat/32/3_2.png) [@szhorvat](https://igraph.discourse.group/u/szhorvat)\
**Post date:** [20 September 2021 06:27 UTC](https://igraph.discourse.group/t/dead-link-in-documentation/492/4 "2021-09-20T06:27:43Z")

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Thanks for the report! In the future, please report problems on the issue tracker. I moved this report there: [Broken links to Nexus in documentation · Issue #438 · igraph/python-igraph · GitHub](https://github.com/igraph/python-igraph/issues/438)

Nexus is unfortunately no longer available, so the references to it will be removed.

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**Author:** ![tamas](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/tamas/32/1261_2.png) [@tamas](https://igraph.discourse.group/u/tamas)\
**Post date:** [20 September 2021 11:37 UTC](https://igraph.discourse.group/t/dead-link-in-documentation/492/5 "2021-09-20T11:37:16Z")

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I have removed the reference and added a GraphML version of the Zachary karate club graph directly to the documentation.