free...

Free στο AMAZON:

http://www.amazon.com/Scale-1-1-000-000-ebook/dp/B00BE2GLBK/ref=ntt_at_ep_dpi_2

http://wiki.redworlds.gr/tiki-index.php?page=%CE%94%CE%B9%CE%B1%CE%BC%CE%B1%CE%BD%CF%84%CE%AE%CF%82+%CE%A6%CE%BB%CF%89%CF%81%CE%AC%CE%BA%CE%B7%CF%82