This paper is in the following e-collection/theme issue:

Web-based and Mobile Health Interventions 

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Works citing "An Internet-Based Guided Self-Help Intervention for Panic Symptoms: Randomized Controlled Trial"

Wouter van Ballegooijen, Heleen Riper, Britt Klein, David Daniel Ebert, Jeannet Kramer, Peter Meulenbeek, Pim Cuijpers
J Med Internet Res 2013 (Jul 29); 15(7):e154 

According to Crossref, the following articles are citing this article (DOI 10.2196/jmir.2362):

(note that this is only a small subset of citations)

1. Ünlü Ince B, Cuijpers P, van 't Hof E, Riper H. Reaching and recruiting Turkish migrants for a clinical trial through Facebook: A process evaluation. Internet Interventions 2014;1(2):74 [CrossRef]