Avila Jewish cemetery: 

https://avilared.com/archive/6047/el-jardin-de-sefarad-sobre-el-cementerio-judio 

Lucena Jewish cemetery:

https://revistaseug.ugr.es/index.php/meahhebreo/article/view/12527/10742

Toledo Jewish cemetery:

Arturo Ruiz Taboada, “La nécropole juive de Tolède : type, construction et distribution des tombes”, in: Paul Salmona and Laurence Sigal (eds.), L’archéologie du judaïsme en France et en Europe, 2011, pp. 287-300.

Seville Jewish cemetery:

https://helvia.uco.es/bitstream/handle/10396/4444/30.pdf?sequence=1&isAllowed=y