Extract string between two delimeter " "

I want a string between two delimeter like " " from below file and also send send output to the file.

Input File,

2007_08_07_IA-0100-014_"January".PDF 
2007_08_07_IA-0100-031_"January February March
April June July".PDF 
2008-02-28_KR-1022-003_"January
febuary
march april
may".CSV

Output File,

January
January February March April june july
January February March April May