How to retain Ajax-found results when getting back the results page via a browser's back button?

I have three levels of pages on a website:

Home page: a website visitor comes to this page, clicks a link, and gets to the Search page.

Search page: It has two dropdowns (called Language and Subject) and an input box. If a visitor selects a value from a dropdown (such as English under Language), the page shows a list of found search results (loaded via Ajax). If the visitor enters text in the input box, he has to click a search button to get results. 10 results are loaded through Ajax on this page and visitors can see more by clicking on a "load more" button, which loads another 10 results via Ajax.

Search Result page: when a visitor clicks on a search result, he is taken to the search result page.

Now comes the issue: When the visitor clicks a browser's back button on a Search Result page, he wants to see the same list of search results he found before going to the Search Result page.

I cannot think of a way to do it, and I would be very grateful if someone has done it before and shares the solution.

Thanks and regards.