Předmluva
Trigonometrie, GDML_Books, (1952), p. 3-4 / Harvested from
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@inbook{404205,
     title = {P\v redmluva},
     booktitle = {Trigonometrie},
     series = {GDML\_Books},
     publisher = {P\v r\'\i rodov\v edeck\'e nakladatelstv\'\i },
     address = {Praha},
     year = {1952},
     pages = {3-4},
     url = {http://dml.mathdoc.fr/item/404205}
}

 (éd.). Předmluva, dans Trigonometrie, GDML_Books,  (1952), pp. 3-4. http://gdmltest.u-ga.fr/item/404205/