@article {Skyrme127,
title = {A non-linear field theory},
volume = {260},
number = {1300},
pages = {127--138},
year = {1961},
doi = {10.1098/rspa.1961.0018},
publisher = {The Royal Society},
abstract = {A unified field theory of mesons and their particle sources is proposed and considered in its classical aspects. The theory has static solutions of a singular nature, but finite energy,characterized by spin directions; the number of such entities is a rigorously conserved constant of motion; they interact with an external meson field through a derivative-type coupling with the spins, akin to the formalism of strong-coupling meson theory. There is a conserved current identifiable with isobaric spin, and another that may be related to hyper-charge. The postulates include one constant of the dimensions of length, and another that is conjectured necessarily to have the value ђc, or perhaps {\textonehalf}ђc, in the quantized theory.},
issn = {0080-4630},
URL = {http://rspa.royalsocietypublishing.org/content/260/1300/127},
eprint = {http://rspa.royalsocietypublishing.org/content/260/1300/127.full.pdf},
journal = {Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences}
}