Timeline of Google Search
"It’s Panda Update 2.1, Not Panda 3.0, Google Says". Search Engine Land. Retrieved February 2, 2014. Schwartz, Barry (May 9, 2011). "Google Panda 3.0"
Timeline of Google Search
"It’s Panda Update 2.1, Not Panda 3.0, Google Says". Search Engine Land. Retrieved February 2, 2014. Schwartz, Barry (May 9, 2011). "Google Panda 3.0"