BOOKS :
Score! The Story of Soccer, Jennie Haw, Crabtree Publishing, New York, 2015, 32 pages.
The Complete Book of Soccer, Clive Gifford & John Malam, Firefly Books, New York, 2016, 320 pages.
The Kingfisher Soccer Encyclopedia, Clive Gifford, Kingfisher, New York, 2016, 144 pages.
WEBSITES:
Soccer Ball Fabrication :
http://www.soccerballworld.com/Soccer_Ball_Construction.htm
http://www.madehow.com/Volume-5/Soccer-Ball.html
http://www.soccerball.com.pk/construct.htm
https://www.soccerballsmanufacturer.com/t/SoccerBallsManufacturingProcess
Different Soccer Balls :
http://activeforlife.com/soccer-balls-around-the-world/
http://www.soccer.com/guide/soccer-ball-guide/
Soccer Ball History :
http://www.soccerballworld.com/History.htm
https://wikispaces.psu.edu/display/PSUSportsMuseum/History+of+the+Soccer+Ball