If you need help to find more resources you can ask in the ArcGIS Online place at Geonet or open an issue on Github
Remember that Esri also provides other interfaces to search and explore ArcGIS Online items, here are some of them:
If you want to learn more about Esri data providers and the ArcGIS REST APIs we used to build this search interface check the Awesome ArcGIS Project.
Here you will find some pre-build searches, if you are not capable of finding what you are looking feel free to ask for help opening one issue: