How to write source on Lope Ruiz de Esparza's document.

I'm getting ready to add the information on Lope Ruiz de Esparza found in the book Catalago de Pasajeros a Indias Volumen VII. While browsing other messages, I found out that the original document was found and made available by Mr. Arturo Ramos (thank you so much) in this group.

I hope somebody who has used this document can help me. I was able to download it from nuestros ranchos, but how do I reference it? Where exactly was it found? Are these books (the original contrataciones) available online? While comparing both documents, I notice that on the Catalogo they transcribe Lope's boss's last name as Manleon and Maleon, while in the original document it looks like Mauleon. I googled both spellings and it looks like Mauleon is the right spelling. Anyways, any help on how to source this document will be greatly appreciated.

Steve in NC