Exercicis sobre la essa online :
https://polimedia.upv.es/visor/?id=53b29352-9870-224a-95ac-47381a728244
http://www.ua.es/personal/robert.escolano/aprenentatge/exercicis/exercicis/aprofundiment/ortografia/essa/essa_01.htm
http://clic.xtec.cat/quaderns/smora/ortografia_esse/html/section_1.htm?&skin=default&js=http://clic.xtec.cat/qv_viewer/dist/html/scripts/&appl=http://clic.xtec.cat/qv_viewer/dist/html/appl/&css=http://clic.xtec.cat/qv_viewer/dist/html/css/
exercicis essa
http://jaimesegundo.edu.gva.es/j2/documentos/departamentos/catala/GRAMATICA/ORTOGRAFIA/LA%20ESSA%20SORDA%20I%20LA%20ESSA%20SONORA.pdf
http://blocs.cpnl.cat/mariaromero/files/2011/09/EXERCICIS-DE-LA-ESSA1.pdf
https://sites.google.com/site/catalapacfgs/8-la-essa-sorda-i-sonora-exercicis