Exer. 18.1
Exer. 18.2
Exer. 18.3 - two solutions
Exer. 18.4
Exer. 18.5 Self-dual and anti-self-dual planes
Exer. 18.05 another 2 solutions
Exer. 18.6
Exer. 18.6 another solution
Exer. 18.7 Geometry on the velocity vector hyperboloid
Exer. 18.7 another solution
Exer. 18.8
Exer. 18.8 another solution
Exer. 18.9
Exer. 18.10
Exer. 18.10 another solution
Exer. 18.11
Exer. 18.12
Exer. 18.12 another solution
Exer. 18.13
Exer. 18.14
Exer. 18.15
Exer. 18.16
Exer. 18.17
Exer. 18.18
Exer. 18.18 another solution
Exer. 18.19
Exer. 18.20
Exer. 18.21
Exer. 18.22