The densest packing of $9$ circles in a square

J. Schaer
1965 Canadian mathematical bulletin  
Packing problems of this kind are obviously equivalent ^o the problems of placing k (here 9) points in a unit square such that the minimum distance between any two of them be as Large as possible. The solutions of these problems are known for 2 < k < 9. The largest possible minimum distances m
doi:10.4153/cmb-1965-018-9 fatcat:x7v3eo6durf5leb3p4irzsesa4