SELECT short_month AS short,
  long_month AS long
FROM month_tbl
ORDER BY decode(UPPER(short_month),
  'JAN',   '01',  
  'FEB',   '02',  
  'MAR',   '03',  
  'APR',   '04',  
  'MAY',   '05',  
  'JUN',   '06',  
  'JUL',   '07',  
  'AUG',   '08',  
  'SEP',   '09',  
  'OCT',   '10',  
  'NOV',   '11',  
  'DEC',   '12');

short       long
JAN     JANUARY
FEB     FEBRUARY
MAR     MARCH
APR     APRIL
MAY     MAY
JUN     JUNE
JUL     JULY
AUG     AUGUST
SEP     SEPTEMBER
OCT     OCTOBER
NOV     NOVEMBER
DEC     DECEMBER