Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2014 Jul 23;3(3):e31. doi: 10.2196/resprot.2599

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

©Lenneke van Genugten, Pepijn van Empelen, Anke Oenema. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 23.07.2014.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Research Protocols, is properly cited. The complete bibliographic information, a link to the original publication on http://www.researchprotocols.org, as well as this copyright and license information must be included.

PMC Copyright notice

resprot_v3i2e31_app1.pdf^{(2.3MB, pdf)}