• enVide neFelibata www.envidenefelibata.com
• The Pocket Arts Guide www.thepocketartsguide.com
• ATCs and ACEOs www.emptyeasel.com
• Kathleen Harrington www.kathleenharrington.com
• Museum of Pocket Art www.mopaonline.com
• Gordon Skalleberg www.gordonskalleberg.wordpress.com
• Andrea Tomkins www.usedeverywhere.com/atc-pocket-art/
• Art-o-mat www.artomat.org
• IUOMA - International Union of Mail-Artists www.iuoma-network.ning.com
• I-nigma QR Code Reader www.i-nigma.com