@article{10_4064_ap_52_2_187_194,
     author = {Ludwik Byszewski},
     title = {Strong maximum and minimum principles for parabolic functional-differential problems with initial inequalities $u(t_0, x) \stack {\ensuremath{\leq}} {(\ensuremath{\geq})}K$},
     journal = {Annales Polonici Mathematici},
     pages = {187--194},
     publisher = {mathdoc},
     volume = {52},
     number = {2},
     year = {1990},
     doi = {10.4064/ap-52-2-187-194},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-52-2-187-194/}
}