Hand drawn Doodle city
Matherials - Moleskine, Liners
To buy these and many other illustrations in the vector here
http://www.shutterstock.com/g/balabolka/sets/1824018-doodles
http://www.istockphoto.com/search/portfolio/4680268
http://www.shutterstock.com/g/balabolka/sets/1824018-doodles
http://www.istockphoto.com/search/portfolio/4680268