Listed below are some resources. Feel free to find other sources to support your position.
http://childparenting.about.com/od/schoollearning/a/year-round-school-pros-cons.htm
http://www.ehow.com/info_8131173_disadvantages-yearround-schools.html
http://vimeo.com/35900457
http://www.washingtonpost.com/wp-dyn/content/article/2009/06/05/AR2009060501971.html
http://www.buzzle.com/articles/year-round-school-pros-and-cons.html
http://neatoday.org/2014/09/04/districts-weigh-pros-and-cons-of-year-round-schools-2/
http://education.seattlepi.com/yearround-school-advantages-disadvantages-2521.html
http://www.theprospect.net/all-day-every-day-the-pros-and-cons-of-year-round-schools-12111
Image from http://www.theprospect.net/all-day-every-day-the-pros-and-cons-of-year-round-schools-12111
http://childparenting.about.com/od/schoollearning/a/year-round-school-pros-cons.htm
http://www.ehow.com/info_8131173_disadvantages-yearround-schools.html
http://vimeo.com/35900457
http://www.washingtonpost.com/wp-dyn/content/article/2009/06/05/AR2009060501971.html
http://www.buzzle.com/articles/year-round-school-pros-and-cons.html
http://neatoday.org/2014/09/04/districts-weigh-pros-and-cons-of-year-round-schools-2/
http://education.seattlepi.com/yearround-school-advantages-disadvantages-2521.html
http://www.theprospect.net/all-day-every-day-the-pros-and-cons-of-year-round-schools-12111