The reason is that the link present in your page is relative to current domain.
You should have a full URL in the page to ensure it is redirected to the correct website.
Solution no 1)
If the editor you are using does not allow to save a full URL when you create the link, you could use a special keyword that you could replace later by our "Search/Replace" plugin.
www.jms2win.com/free-download/doc_downlo...rch--replace-utility
This could give you a workarround.
ie. the link could be written {master}index.php?option=com_content&catid=37&id=180&view=article&Itemid=233
and ask the plugin to replace {master} by
www.master.com
In such way, the URL would be always
www.master.com/index.php?option=com_cont...ticle&Itemid=233
The disadvantage of this solution is that you are redirected to the website that has created the article.
Solution no 2)
Another solution could be to use the link created by a menu item on the articles sharing.
To do that, create a temporary menu entry and select the "MultiSites article layout" or another layout.
There you will be able to select the site and the article.
Once the menu item is save, you can re-open it and copy the link created for this item.
You should have something like
index.php?option=com_multisitescontent&view=article&site_id=XXXXX&id=NNNNN
If you have a look on the link in detail, you will see that the option is different (multisitescontent) and that you have an additional parameter (site_id).
The advantage of the solution no 2 is that you remain on the same domain and you just display the articles from another website.