# External data

The following is a list of the external data sources used, including what they are used for, and how often the data is updated.

### Citations

Data source: [OpenAlex](https://docs.openalex.org/)

Update frequency: Quarterly (4x per year)

Used in Unsub: Journal level [Cost Per Use](/reference/cost-per-use-cpu.md) calculation (if you include citations in your [scenario parameters](/reference/scenarios/scenario-parameters.md#citation-and-authorship)). Citations data shown in [single journal view](/reference/single-journal-view.md) or in the table view in a scenario. Institutional level [APC Report](/how-to-guides/apc-report.md).

### Authorships

Data source: [OpenAlex](https://docs.openalex.org/)

Update frequency: Quarterly (4x per year)

Used in Unsub: Journal level [Cost Per Use](/reference/cost-per-use-cpu.md) calculation (if you include authorships in your [scenario parameters](/reference/scenarios/scenario-parameters.md#citation-and-authorship)). Authorships data shown in [single journal view](/reference/single-journal-view.md) or in the table view in a scenario. Institutional level [APC Report](/how-to-guides/apc-report.md).

### Journal metadata

This includes journal title, ISSNs, publisher, open access status, and whether title is currently publishing (based on date of last DOI published).

Data source: [OpenAlex](https://docs.openalex.org/)

Update frequency: Daily

Used in Unsub: Determine whether a journal should be included in Unsub dashboards or not (see [Why don't I see a certain title in my dashboard?](/troubleshooting/why-dont-i-see-a-certain-title-in-my-dashboard.md)), and as the source of truth to link together journals, user uploaded data, and any external journal level data.

### Journal embargo periods

Data source: Manually collected. We will soon switch over to using data from [oa.works](<https://oa.works/ >)

Update frequency: Not currently updated

Used in Unsub: Shown in [single journal view](/reference/single-journal-view.md) in Unsub dashboards, and used in calculating [Cost Per Use](/reference/cost-per-use-cpu.md)

### Publisher societies

Data source: Manually collected.

Update frequency: Not currently updated

Used in Unsub: Shown in [single journal view](/reference/single-journal-view.md) in Unsub dashboards

### Number of papers

Data source: [OpenAlex](https://docs.openalex.org/)

Update frequency: Daily

Used in Unsub: Journal level usage forecast.

### ROR and Grid identifiers

Data source: Microsoft Academic Graph

Update frequency: Not currently updated; we'll switch to OpenAlex in the near future.

Used in Unsub: Used to link together many kinds of data (journals, authors, etc.) to institutions.

### APC prices

Data source: [We get these from publisher websites](/how-it-works/where-do-the-apc-prices-come-from.md).

Update frequency: Not updated

Used in Unsub: For the institutional [APC Report](/how-to-guides/apc-report.md) for the big five publishers (Elsevier, Wiley, Springer Nature, Taylor & Francis, SAGE) only.

### Unpaywall

Data source: [Unpaywall](https://unpaywall.org/)

Update frequency: Every 6 hours (4x/day)

Used in Unsub: Used to determine usage patterns at a journal title level. Also used in creating citation and authorship data (see above for how citation and authorship data are used).

### Unpaywall Browser Extension

Data source: [Unpaywall](https://unpaywall.org/) Browser Extension data; aggregated statistics about journal-level year of publication usage derived from usage of people with the Unpaywall browser extension installed

Update frequency: Updated October 2022. Likely update frequency: annual

Used in Unsub: Used to determine usage patterns at a journal title level.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.unsub.org/reference/external-data.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.