Owen L. Astrachan Susanne E. Hambrusch Joan Peckham Amber Settle The present and future of computational thinking. 549-550 2009 SIGCSE http://doi.acm.org/10.1145/1508865.1509053 conf/sigcse/2009 db/conf/sigcse/sigcse2009.html#AstrachanHPS09