References:

• http://www.cyclorama.net/viewArticle.php?id=250
• http://en.wikipedia.org/wiki/File:Quadricycle_Intl_Q-cycle-6_06.JPG
• http://www.treehugger.com/bikes/13-quadracycles-four-wheeled-bike-round-up/page2.html
• http://www.treehugger.com/bikes/13-quadracycles-four-wheeled-bike-round-up.html
• http://www.treehugger.com/clean-technology/toyota-unveil-hybrid-pedal-electric-concept-a-caratm.html
• http://www.tandem-bicycle-central.com/quadricycle.html
• http://i1.wp.com/bandra.info/wp-content/uploads/2013/05/cycle4.jpg?resize=597%2C446
• http://www.thehindubusinessline.com/news/science/walking-or-cycling-to-work-can-boost-heart-health-in-indians/article4807356.ece
• http://bicyclelab.com/wp-content/uploads/DSC_0231.jpg
• http://alpenatweed.blogspot.in/2012/05/wear-hinny-meets-saddle.html
• http://www.cyclorama.net/viewProduct.php?id=348
• http://rhoadescardealer.com/irontonrhoadescar/files/2013/01/IMG_0279.jpg
• http://digital.hammacher.com/Items/11968/11968_1000x1000.jpg
• http://locallygrownnorthfield.org/wp-content/uploads/2010/11/wpid-IMG_20101106_172046.jpg
• online.wsj.com/news/articles/SB10001424052702303459004577361371344711312
• www.maciejdakowicz.com/files/posts/2417/india_mumbai_street_photography_workshop_tuition_course_tour_marine_drive_nariman_point_exercising_larry_hallegua.jpg
• http://www.sikhchic.com/sports/cms/articles/photo1/Fauja-101-a.jpg
• http://tourdefours.files.wordpress.com/2013/09/cf035910-11.jpg
• http://www.rhoadescar.com/images/solaride-model.jpg
• http://bicycledesign.net/wp-content/uploads/2012/08/6085286664_5e4a90b0f0_b-498x297.jpg
• http://media.cleveland.com/roadrant_impact/photo/11796035-standard.jpg
• http://www.surreycompany.com/images/IMG_4066_000.JPG
• http://tourdefours.files.wordpress.com/2013/09/cf035910-11.jpg
• http://bicycledesign.net/2012/08/rishock-a-pedal-assist-electric-quadricycle/
• http://gas2.org/files/2009/06/sohh-project-3.jpg
• http://www.cyclorama.net/images/galleryImages/img151-lrg.jpg
• http://recklesscognition.files.wordpress.com/2008/08/bicycle_disc_brake.jpg
• http://www.ergonomickneelingchairs.org/wp-content/uploads/2011/01/chair11-300x300.jpg
• http://www.lifespanfitness.com/media/wysiwyg/LifeSpan-C3i-Seat-Adjustability.png
• http://product-images.www8-hp.com/digmedialib/prodimg/lowres/c02769363.png
• http://www.atomiczombie.com/plans/tradewinds/TradeWinds%20Recumbent%20Tandem%20Bike%204.jpg
• http://brucemctague.com/wp-content/uploads/2011/11/Togetherness_by_cyberlilly.jpg
• http://www.ttrweekly.com/site/wp-content/uploads/2010/06/Togetherness.jpg
• http://thumbs.dreamstime.com/z/togetherness-10494769.jpg
• http://static7.depositphotos.com/1278120/770/i/450/dep_7703687-Togetherness---Business.jpg
• http://31.media.tumblr.com/c92b74251c8d05534eab842febdf5c27/tumblr_mu1m0cx1UG1qa1k2ao1_500.jpg
• http://www.mynewsletterbuilder.com/ex/template_content_corner/ex90/images/familybiking.jpg
• http://momitforward.com/wp-content/uploads/2010/08/iStock_000008810869Medium-1024x682.jpg
• http://www.healthbarnusa.com/wp-content/uploads/2012/12/active_family_000013291670small.jpg?4c0b9c
• http://www.beltrance.com/blog/wp-content/uploads/2011/01/Hub-Centre-SteeringDemonstener-Difazio-designed-by-Carlos-Beltr%C3%A1n-5-300x158.jpg
• http://cdn.c.photoshelter.com/img-get/I00001EpiH7TQJNI/s/750/750/AUS-05-11-06283.jpg
• http://tourism.atdw.com.au/multimedia/tvic/ATDW_Extra_Large_Landscape__9229496_BY25_SavannahWalkaboutKangaroo
• http://jackimad.files.wordpress.com/2013/05/article-2239510-163e27bc000005dc-102_964x530.jpg
• http://riekesna.files.wordpress.com/2012/01/sharpchickadee001.jpg
• http://1.bp.blogspot.com/-Zz4fc5tAD4c/T9HpGvvYuGI/AAAAAAAABS8/8Qm1fm-n864/s1600/flight+puffin+01.jpg
• http://4.bp.blogspot.com/-bB0KJuzSego/UHb0esZFS-I/AAAAAAAABzI/y0GZ-dcsnFA/s1600/dance.jpg
• http://exeuntmagazine.com/wp-content/uploads/armitage-600x372.png

Case Study Download:
• Qudracycle - Four-wheeled human-powered land vehicle......