@article{700562,
     title = {Maps of extremally disconnected spaces, theory of types, and applications},
     booktitle = {General Topology and Its Relations to Modern Analysis and Algebra},
     series = {GDML\_Books},
     publisher = {Academia Publishing House of the Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1971},
     pages = {[131]-142},
     mrnumber = {MR0295305},
     zbl = {0248.54045},
     url = {http://dml.mathdoc.fr/item/700562}
}

Frolík, Z. Maps of extremally disconnected spaces, theory of types, and applications, dans General Topology and Its Relations to Modern Analysis and Algebra, GDML_Books,  (1971), pp. [131]-142. http://gdmltest.u-ga.fr/item/700562/