Milne's book provides an excellent introduction to the study of inviscid airflow using potential theory. The text begins with 2D airfoil analysis via complex transformation techniques (conformal mapping). It then progresses to 3D finite wing theory using lifting line and lifting surface theory. I concludes with chapters on wind tunnel corrections, propellers, swept wings (sub and supersonic flow), and basic stability theory. A reference book dealing with conformal mapping and complex numbers may be helpful. For this I easily recommend another 5-star book, "Complex Variables and the Laplace Transform for Engineers" by Wilbur R. Lepage.