G7IV

JM53, MK73, and Houk88 do not list a G7IV standard.

Keenan89 lists HD 20618 as a G7IV standard, plus a variant: HD 182572
(G7IV Hdel1).

# Standard
HD 20618 = HR 995 = 59 Ari 
  G7IV: Keenan89
  G8IV: Jaschek78(Harlan69)
  G5: Cannon
  Should be considered "G7IV" standard