Carta comecial

http://www.brasilescola.com/redacao/carta-comercial.htm

http://www.pcspeed.com.br/dic4.html

memorando

http://www.tudobox.com/153/modelo_de_memorando.html

http://www.correafabio.com/2010/04/modelo-de-memorando-1.html

cartas circular

http://www.tudobox.com/373/modelo_de_carta_circular.html

http://www.correafabio.com/2009/06/modelo-de-carta-circular-oferecendo.html