@Article{ authors = " Krystian Heffner, Małgorzata Twardzik", title = "Wpływ detalicznych sieci handlowych na rozwój lokalny miałych miast i obszarów wiejskich w województwie śląskim ", journal = "Space - Society - Economy", issue = "2020 / Numer 31", pages = "45 - 60" }

@Article{ authors = " Krystian Heffner, Brygida Solga", title = "Factors shaping the economic migrations after accession of Poland to the European Union / Krystian Heffner, Brygida Solga.", journal = "Bulletin of Geography. Socio-Economic Series", issue = "2004 / Numer 3", pages = "115 - 123" }

@Article{ authors = " Krystian Heffner, Brygida Solga", title = "Features of a migration region - an analysis using the example of the Opolskie Voivodship / Krystian Heffner, Brygida Solga.", journal = "Bulletin of Geography. Socio-Economic Series", issue = "2013 / Numer 20", pages = "43 - 58" }

@Article{ authors = " Krystian Heffner, Brygida Solga", title = "Small towns as local economic centres in rural areas / Krystian Heffner, Brygida Solga.", journal = "Bulletin of Geography. Socio-Economic Series", issue = "2006 / Numer 6", pages = "77 - 87" }

@Article{ authors = " Krystian Heffner", title = "Poziom metropolitalności wybranych ośrodków w Polsce : znaczenie wag i zmiennych", journal = "Acta Universitatis Lodziensis. Folia Oeconomica", issue = "2013 / Numer 293", pages = "11 - 26" }

@Article{ authors = " Krystian Heffner, Brygida Solga", title = "Foreign migration of Poles in scientific research at the turn of century / Krystian Heffner, Brygida Solga.", journal = "Bulletin of Geography. Socio-Economic Series", issue = "2008 / Numer 10", pages = "49 - 61" }