ISBN-13: 9781107493933 / Angielski / Miękka / 2015 / 100 str.
Originally published in 1908 as number nine in the Cambridge Tracts in Mathematics and Mathematical Physics series, this book provides a concise account regarding the invariant theory connected with a single quadratic differential form. This book will be of value to anyone with an interest in quadratic differential forms and the history of mathematics.