EN 
| Letter | Year |
|---|---|
| June 1968 – VOL. 49, No. 6 – Updating the Calendar | June 1968 |
| May 1968 – VOL. 49, No. 5 – Technology as a Way of Life | May 1968 |
| April 1968 – VOL. 49, No. 4 – In the Long Run | April 1968 |
| March 1968 – VOL. 49, No. 3 – About Writing Letters | March 1968 |
| February 1968 – VOL. 49, No. 2 – Fatal Home Accidents CAN be Avoided | February 1968 |
| January 1968 – VOL. 49, No. 1 – International Year for Human Rights | January 1968 |
| December 1967 – VOL. 48, No. 12 – Something about Retirement | December 1967 |
| November – VOL. 48, No. 11 – After the Centenary, Whither Now? | November 1967 |
| October 1967 – VOL. 48, No. 10 – Communication is Vital | October 1967 |
| September 1967 VOL. 48, NO. 9 – The Inefficiency of Waste | September 1967 |