— Eric Enge and Stephan Spencer and Jessie Stricchiola and and Rand Fishkinconcept of considering temporal factors in link analysis is documented in a US patent held by Google that you can look up by searching for patent number 20050071741.
Replicated under Fair Use from The Art of SEO by Eric Enge and Stephan Spencer and Jessie Stricchiola and and Rand Fishkin.