https://www.amazon.com/Modern-Information-Retrieval-Concepts-Technology/dp/0321416910/ref=pd_sim_14_2?_encoding=UTF8&psc=1&refRID=PA193S6R7J5XV0SKEDH3
http://ciir.cs.umass.edu/downloads/SEIRiP.pdf
https://www.amazon.com/Search-Engines-Information-Retrieval-Practice/dp/0136072240/ref=pd_sim_14_3?_encoding=UTF8&psc=1&refRID=MS3RG1HPC5DPHG7GE53E