Sokolsky 1.b4
Grob's Attack 1.g4
Q-Knight Attack 1.Nc3
Slow Stuff
The Table of Contents tells it all: (1) Games that Shook the World; (2) Future Wars with g4; (3) Queen’s Knight Attack (1 Nc3); (4) Slow Stuff (1 e3, 1 d3, 1 c3, 1 a3, 1 h3); (5) Totally Disreputable (1 h4, etc.); and (6) Sokolsky 1 b4.
Although there now are books dedicated to some of these more unusual lines, Harding’s two-volume series (see also Dynamic Black Openings) was a groundbreaker in many ways. These books still retain their relevance and contain many ideas for the imaginative chessplayer.