@article{RSMUP_1981__64__1_0,
     author = {Vatsala, A. S. and Vaughn, R. L.},
     title = {Existence of extremal solutions and comparison results for delay differential equations in abstract cones},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {1--14},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {64},
     year = {1981},
     mrnumber = {636622},
     zbl = {0507.34063},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_1981__64__1_0/}
}