Example of a Requirements Document

Link to what I think is a good but concise requirements document - specifying reuqirements for a Travel App:

http://www.citysdk.eu/wp-content/uploads/2013/09/DELIVERABLE_WP4_TA_SRS_0.21.pdf

I think its a good requirement as it has simple visuals, in form of sketches with respect to the requirements to this app.