Question:
Who was the head of Romania in Jun, 1939?

Context:
 Ion Emanuel Florescu is the head of the government of Romania from Mar, 1891 to Dec, 1891. 
 Theodor Rosetti is the head of the government of Romania from Mar, 1888 to Mar, 1889. 
 Octavian Goga is the head of the government of Romania from Dec, 1937 to Feb, 1938. 
 Mihai Răzvan Ungureanu is the head of the government of Romania from Feb, 2012 to May, 2012. 
 Miron Cristea is the head of the government of Romania from Feb, 1938 to Mar, 1939. 
 Armand Călinescu is the head of the government of Romania from Mar, 1939 to Sep, 1939. 
 Ion Gheorghe Maurer is the head of the government of Romania from Mar, 1961 to Feb, 1974. 
 Emil Boc is the head of the government of Romania from Dec, 2008 to Feb, 2012. 
 Nicolae Crețulescu is the head of the government of Romania from Jun, 1865 to Feb, 1866. 
 Barbu Catargiu is the head of the government of Romania from Feb, 1862 to Jun, 1862. 
 Mihail Kogălniceanu is the head of the government of Romania from Oct, 1863 to Jan, 1865. 
 Petre Roman is the head of the government of Romania from Dec, 1989 to Oct, 1991. 
 Călin Popescu-Tăriceanu is the head of the government of Romania from Dec, 2004 to Dec, 2008. 
 Alexandru G. Golescu is the head of the government of Romania from Feb, 1870 to Apr, 1870. 
 Take Ionescu is the head of the government of Romania from Dec, 1921 to Jan, 1922. 
 Ludovic Orban is the head of the government of Romania from Nov, 2019 to Dec, 2020. 
 Manea Mănescu is the head of the government of Romania from Feb, 1974 to Mar, 1979. 
 Ion Gigurtu is the head of the government of Romania from Jul, 1940 to Sep, 1940. 
 Ion C. Brătianu is the head of the government of Romania from Jun, 1881 to Mar, 1888. 
 Radu Vasile is the head of the government of Romania from Apr, 1998 to Dec, 1999. 
 Ilie Verdeț is the head of the government of Romania from Mar, 1979 to May, 1982. 
 Mihai Tudose is the head of the government of Romania from Jun, 2017 to Jan, 2018. 
 Ion G. Duca is the head of the government of Romania from Nov, 1933 to Dec, 1933. 
 Petru Groza is the head of the government of Romania from Mar, 1945 to Jun, 1952. 
 Nicolae Văcăroiu is the head of the government of Romania from Nov, 1992 to Dec, 1996. 
 Florin Cîțu is the head of the government of Romania from Dec, 2020 to Nov, 2021. 
 Viorica Dăncilă is the head of the government of Romania from Jan, 2018 to Nov, 2019. 
 Gheorghe Gheorghiu-Dej is the head of the government of Romania from Jun, 1952 to Oct, 1955. 
 Dimitrie Sturdza is the head of the government of Romania from Apr, 1897 to Apr, 1899. 
 Ion Ghica is the head of the government of Romania from Dec, 1870 to Mar, 1871. 
 Nicolae Ciucă is the head of the government of Romania from Nov, 2021 to Dec, 2022. 
 Sorin Grindeanu is the head of the government of Romania from Jan, 2017 to Jun, 2017. 
 Petre S. Aurelian is the head of the government of Romania from Dec, 1896 to Apr, 1897. 
 Nicolae Iorga is the head of the government of Romania from Apr, 1931 to Jun, 1932. 
 Theodor Stolojan is the head of the government of Romania from Oct, 1991 to Nov, 1992. 
 Dimitrie Ghica is the head of the government of Romania from Nov, 1868 to Jan, 1870. 
 Dimitrie Brătianu is the head of the government of Romania from Apr, 1881 to Jun, 1881. 
 Mugur Isărescu is the head of the government of Romania from Dec, 1999 to Dec, 2000. 
 Victor Ponta is the head of the government of Romania from May, 2012 to Nov, 2015. 
 Constantin Bosianu is the head of the government of Romania from Jan, 1865 to Jun, 1865. 
 Victor Ciorbea is the head of the government of Romania from Dec, 1996 to Apr, 1998. 
 Ștefan Golescu is the head of the government of Romania from Nov, 1867 to May, 1868. 
 Constantin Sănătescu is the head of the government of Romania from Aug, 1944 to Dec, 1944. 
 Gheorghe Tătărescu is the head of the government of Romania from Jan, 1934 to Dec, 1937. 
 Nicolae Rădescu is the head of the government of Romania from Dec, 1944 to Feb, 1945. 
 Dacian Cioloș is the head of the government of Romania from Nov, 2015 to Jan, 2017. 
 Manolache Costache Epureanu is the head of the government of Romania from May, 1876 to Aug, 1876. 
 Constantin Dăscălescu is the head of the government of Romania from May, 1982 to Dec, 1989. 
 Gheorghe Argeșanu is the head of the government of Romania from Sep, 1939 to Sep, 1939. 
 Constantin Argetoianu is the head of the government of Romania from Sep, 1939 to Nov, 1939. 
 Lascăr Catargi is the head of the government of Romania from Dec, 1891 to Oct, 1895. 
 Adrian Năstase is the head of the government of Romania from Dec, 2000 to Dec, 2004. 
 Nicolae Golescu is the head of the government of Romania from May, 1868 to Nov, 1868. 
 Chivu Stoica is the head of the government of Romania from Oct, 1955 to Mar, 1961.

Answer:
Armand Călinescu