Who is the person that started the concept of magnetic helicity? Is it Gauss? Is it Woltjer? I was trying to obtain a copy of Woltjer's paper of 1958 Proc. Natl Acad. Sci. USA 44 480. Can anybody help me get a copy of this paper? I did purchased a paper by Mitchell A. Berger called "Introduction to magnetic helicity," Plasma Phys. Control. Fusion 41 (1999) B167-B175. I first saw the concept in the book by Arnab Rai Choudhuri called "The Physics of Fluids and Plasma, an introduction for Astrophysicists." Is the idea of magnetic helicity connected to some form of perpetual energy?