For a free copy of Atomic simply send an A5 stamped addresed envelope to:
Atomic Publications
29 Dinsmore Road
London
SW12 9PT
United Kingdom

For UK applications please put 29p worth of stamps on the envelope. For European applications please include 2 International Reply Coupons (just ask for them at your local Post Office). Outside Europe please include 4 International Reply Coupons. Very soon you will have the House of Atomic's finest flying through the post to you!