Table: tv_episode_data_13
Columns: no_in_series
no_in_season
title
directed_by
written_by
original_air_date
production_code
u_s_viewers_millions

Question: what is the No in series when Rob wright & Debra j. Fisher & Erica Messer were the writers?
SQL: SELECT MIN("no_in_series") FROM tv_episode_data_13 WHERE "written_by" = 'Rob Wright & Debra J. Fisher & Erica Messer'

Question: what was the name of the episode that got 3.3 (millions) of u.s viewers?
SQL: SELECT "title" FROM tv_episode_data_13 WHERE "u_s_viewers_millions" = '3.3'

Question: who were the directors of the episode called "someone to witch over me"?
SQL: SELECT "directed_by" FROM tv_episode_data_13 WHERE "title" = '"Someone to Witch Over Me"'

Question: In season number 3,  who were the writers?
SQL: SELECT "written_by" FROM tv_episode_data_13 WHERE "no_in_season" = 3

Question: when the writer is Brad Kern, how many u.s viewers (in millions) had the episode?
SQL: SELECT "u_s_viewers_millions" FROM tv_episode_data_13 WHERE "written_by" = 'Brad Kern'