Poetry Foundation: Æmilia Lanyer
https://www.poetryfoundation.org/poets/aemilia-lanyer
Contains a biography of Lanyer and an analysis of Salve Deus Rex Judaeorum.
The British Library: Salve Deus Rex Judaeorum
https://www.bl.uk/collection-items/emilia-laniers-salve-deus-rex-judaeorum-1611
Scans of the poem "Salve Deus Rex Judaeorum" and a short introduction to Lanyer.
Oxford Bibliographies: Aemilia Lanyer
https://www.oxfordbibliographies.com/view/document/obo-9780195399301/obo-9780195399301-0434.xml
A biography and bibliography on Lanyer.