> ## Documentation Index
> Fetch the complete documentation index at: https://developers.openalex.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Countries Overview

> Schema reference for Countries entities

Countries represent geographic nations. They are used for filtering works by author affiliation country, and for understanding the geographic distribution of research.

## Filter, sort, and group\_by fields

The API supports filtering, sorting, and grouping on countries fields. See [Filtering](/guides/filtering), [Sorting](/guides/sort), and [Grouping](/guides/grouping) for syntax.

Fields marked **(deprecated)** are `.search` filters — use the [`search` parameter](/guides/searching) instead.

| Field                                  | Sort | Group\_by | Filter |
| -------------------------------------- | :--: | :-------: | :----: |
| `cited_by_count`                       |   ✓  |     ✓     |    ✓   |
| `default.search` **(deprecated)**      |      |           |    ✓   |
| `display_name`                         |   ✓  |           |    ✓   |
| `display_name.search` **(deprecated)** |      |           |    ✓   |
| `from_created_date`                    |   ✓  |           |    ✓   |
| `id`                                   |   ✓  |     ✓     |    ✓   |
| `works_count`                          |   ✓  |     ✓     |    ✓   |