What are the first names of S. F. Buck?
According to Google Scholar, the author's first name is Samuel.

To find this, I did the following:


Do a Google Scholar search for one of S. F. Buck's papers; I chose the following paper which was linked in a comment above: A Method of Estimation of Missing Values in Multivariate Data Suitable for use with an Electronic Computer 
Click on the "cite" link (quote symbol) at the Google Scholar result for the above paper
The MLA and Chicago citation style formats both list the author's first name as Samuel