Question: Which one of the women's service magazines "Seven Sisters" originally published part of Edgar Rice Burroughs' Tarzan the Untamed?

Context paragraphs:
Tarzan: Return to Pal-ul-don: Tarzan: Return to Pal-ul-don is a novel written by Will Murray featuring Edgar Rice Burroughs's jungle hero Tarzan.  It is the first volume in the series The Wild Adventures of Tarzan, a series of new works authorized and licensed by Edgar Rice Burroughs, Inc. It was first published by Altus Press in June 2015 in trade paperback and ebook.

Carson of Venus: Carson of Venus is the third book in the Venus series (Sometimes called the "Carson Napier of Venus series") by American writer Edgar Rice Burroughs.  Burroughs wrote the novel in July and August 1937.  It was serialized in 1938 in six weekly installments from January 8 to February 12 in "Argosy", the same publication where the previous two Venus novels appeared.  It was published in book form a year later from Edgar Rice Burroughs, Inc. Burroughs originally submitted the novel to a number of the "slick" magazines: "Liberty", "The Saturday Evening Post", "Collier's", and "Ladies' Home Journal".  All rejected the story.

Tarzan on the Precipice: Tarzan on the Precipice is a novel written by Michael A. Sanford featuring Edgar Rice Burroughs's jungle hero Tarzan.  It is the second volume in the series The Wild Adventures of Tarzan, a series of new works authorized, licensed and published by Edgar Rice Burroughs, Inc. It was first published in May 2016 in trade paperback, with a hardcover edition released in the following June and an ebook version the following September.

Tarzan and Jane (TV series): Tarzan and Jane (or Edgar Rice Burroughs' Tarzan and Jane) is an American–Canadian computer-animated web series, produced by Arad Animation, 41 Entertainment and Arc Productions and is based on the 1912 novel "Tarzan of the Apes" by Edgar Rice Burroughs.

I Am a Barbarian: I Am a Barbarian is a historical novel by Edgar Rice Burroughs written in 1941 but was not published until after the author's death, first appearing in hardback on September 1, 1967 as published by Edgar Rice Burroughs, Inc..  The book was originally to have been published by Canaveral Press.  When Canaveral stopped adding titles to its catalog, Edgar Rice Burroughs, Inc. took up the project.  It was the first book the firm had published since "Llana of Gathol", in 1948.  "I Am a Barbarian" is one of only two historical novels Burroughs wrote.  The other, "The Outlaw of Torn", set in the England of King Henry III, was published in 1927.

Tarzan the Magnificent (novel): Tarzan the Magnificent is a book by American writer Edgar Rice Burroughs, the twenty-first in his series of books about the title character Tarzan.  It was originally published as two separate stories serialized in different pulp magazines; "Tarzan and the Magic Men" in "Argosy" from September to October, 1936, and "Tarzan and the Elephant Men" in "Blue Book" from November 1937 to January 1938.  The two stories were combined under the title "Tarzan the Magnificent" in the first book edition, published in 1939 by Edgar Rice Burroughs, Inc. In order of writing, the book follows "Tarzan's Quest" and precedes "Tarzan and the Forbidden City".  In order of book publication it falls between the latter and "Tarzan and the Foreign Legion".  The novel's plot bears no relation to that of the 1960 film of the same title.

Tarzan the Ape Man (1932 film): Tarzan the Ape Man is a 1932 Pre-Code, American action adventure film featuring Edgar Rice Burroughs' famous jungle hero Tarzan and starring Johnny Weissmuller, Neil Hamilton, C. Aubrey Smith and Maureen O'Sullivan.  It was Weissmuller's first of 12 "Tarzan" films.  The film is loosely based on Burroughs' novel "Tarzan of the Apes" from approximately two decades earlier, with the dialogue written by Ivor Novello.  The film was directed by W. S. Van Dyke.  Metro-Goldwyn-Mayer released two remakes of "Tarzan, the Ape Man" in 1959 and in 1981, but each was a different adaptation of Rice Burroughs' novel.

Tarzan the Untamed: Tarzan the Untamed is a book by American writer Edgar Rice Burroughs, the seventh in his series of books about the title character Tarzan.  It was originally published as two separate stories serialized in different pulp magazines; "Tarzan the Untamed" (also known as "Tarzan and the Huns") in "Redbook" from March to August, 1919, and "Tarzan and the Valley of Luna" in "All-Story Weekly" from March to April 1920.  The two stories were combined under the title of the first in the first book edition, published in 1920 by A. C. McClurg.  In order of writing, the book follows "Jungle Tales of Tarzan", a collection of short stories about the ape-man's youth.  Chronologically, it follows "Tarzan and the Jewels of Opar".

Tarzan Trilogy: Tarzan Trilogy is a collection of original adventure novellas written by Thomas Zachek featuring Edgar Rice Burroughs's jungle hero Tarzan.  It is the third volume in the series The Wild Adventures of Tarzan, a series of new works authorized, licensed and published by Edgar Rice Burroughs, Inc. It was first published on December 14, 2016 in trade paperback, with a hardcover edition released the next day.

Redbook: Redbook is an American women's magazine published by the Hearst Corporation.  It is one of the "Seven Sisters", a group of women's service magazines.

Supporting paragraphs: Tarzan the Untamed Redbook
Answer: Redbook