http://www.ehow.com/how_4537018_up-random-survey-friends-laugh.html

http://www.feedrat.com/Art/108692/48/Looking-For-A-Way-To-Really-Make-Your-Friends-Laugh.html

http://www.ecardfunny.com/friendship/just-for-fun/

http://www.associatedcontent.com/article/2019598/make_your_friends_laugh_with_the_fun.html

http://www.abebooks.com/search/isbn/0192762915

http://www.ecardfunny.com/birthday-cards

http://www.123greetings.com/events/lets_laugh_day/

http://www.ehow.com/how_4896923_free-gag-gifts.html

http://www.123greetings.com/events/laugh_week/

http://www.theshrunkenheads.com/make-your-friend-laugh.html