A study on postal promotion of aerogrammes has recently been published. The study lists and describes in detail meter marks, slogan cancels and the odd ephemera postal authorities have used to promote aerogrammes.
The study is available as a pdf-download for free. Here is how to get it:
- Become a member of stampboards.comwww.stampboards.com
This is the world's greatest forum for philatelists and membership is for free. - Send a request for a download link
Once you are a member go to the thread related to that publication
http://www.stampboards.com/viewtopic.php?f=19&t=73411
and add a post to the thread. The author will then contact you by email and send you the download link.