[1] DCMI: Dublin Core™ Collection Description Frequency Vocabulary, 2021-01-11T08:57:08.000Z, 2021-01-13T09:37:26.916Z https://www.dublincore.org/specifications/dublin-core/collection-description/frequency/

[2] DCMI: Dublin Core™ Collection Description Terms, 2021-01-18T09:36:38.000Z, 2021-01-18T11:25:31.009Z https://www.dublincore.org/specifications/dublin-core/collection-description/collection-terms/#cldFrequency

[3] DCMI: Domains and Ranges for DCMI Properties, 2021-01-18T09:36:38.000Z, 2021-01-20T08:33:36.927Z https://www.dublincore.org/specifications/dublin-core/domain-range/#Frequency