Über Systeme reeller algebraischer Gleichungen
Compositio Mathematica, Volume 7  (1940), p. 1-19
@article{CM_1940__7__1_0,
     author = {Behrend, Felix},
     title = {\"Uber Systeme reeller algebraischer Gleichungen},
     journal = {Compositio Mathematica},
     publisher = {Johnson Reprint Corporation},
     volume = {7},
     year = {1940},
     pages = {1-19},
     zbl = {0021.29301},
     language = {de},
     url = {http://www.numdam.org/item/CM_1940__7__1_0}
}
Behrend, Felix. Über Systeme reeller algebraischer Gleichungen. Compositio Mathematica, Volume 7 (1940) , pp. 1-19. http://www.numdam.org/item/CM_1940__7__1_0/