Question: What is the best-seller by Ruta Sepetys?

Context paragraphs:
La Ruta Moskitia Ecotourism Alliance: The La Ruta Moskitia Ecotourism Alliance is a collection of six indigenous communities that provide ecotourism products and services within the Rio Platano Biosphere Reserve in Honduras.  All of the ecotourism enterprises that are a part of La Ruta Moskitia are 100% community-owned and operated.  All of the financial benefits of the sustainable tourism initiatives of La Ruta Moskitia go directly to local communities.  The benefits of sustainable tourism practices help prevent locals from over hunting, over fishing, and over using the land in the bioreserve.  This alliance was initiated with support of Rare, the conservation and wild life protection organization, and the United Nations because of the joint community and conservation benefits la Ruta Moskitia Ecotourism Alliance promotes.

Salt to the Sea: Salt to the Sea is a 2016 historical fiction young adult novel by Ruta Sepetys.  It tells the story of four individuals in World War II who make their way to the ill-fated MV "Wilhelm Gustloff".  The story also touches on the disappearance of The Amber Room, a work of art stolen by the Nazis that has never been recovered.

La Ruta de los Conquistadores: La Ruta de los Conquistadores, known as the first mountain bike race of its kind, is a multi-stage race held in Costa Rica.  La Ruta de los Conquistadores consists of crossing Costa Rica from the Pacific to the Atlantic Coast in the course of three days.  It is an individual race, covering approximately 400 km of terrain.  First staged in 1992, the three-day race tests athletes with its 8000 (approx.)  meters of elevation gain and strong climate changes.  The event is also open to amateurs, having a 12-hour window to finish each stage, if competitors do not finish they are still welcome to race the next day but their cumulative times will not count on the overall results.  “La Ruta de los Conquistadores pushes some of the world’s strongest mountain bikers to their limits on one of the toughest, most beautiful courses on Earth.”  Kevin Vermaak, founder of the Cape Epic event in South Africa, took inspiration in La Ruta de los Conquistadores.

Out of the Easy: Out of the Easy is a 2013 novel by Ruta Sepetys.  It is her second published novel.  It features Josie Moraine, a young woman in the 1950s French Quarter of New Orleans who struggles to escape her family and become the author of her own destiny.  The novel became a New York Times bestseller and was chosen as an Editor’s Choice in the New York Times on February 15, 2013.

Ruta graveolens: Ruta graveolens, commonly known as rue, common rue or herb-of-grace, is a species of "Ruta" grown as an ornamental plant and herb.  It is native to the Balkan Peninsula.  It is now grown throughout the world in gardens, especially for its bluish leaves, and sometimes for its tolerance of hot and dry soil conditions.  It is also cultivated as a medicinal herb, as a condiment, and to a lesser extent as an insect repellent.

Ashes in the Snow: Ashes in the Snow is a World War II drama based on the best-seller "Between Shades of Gray" by Ruta Sepetys.

Between Shades of Gray: Between Shades of Gray, a New York Times Bestseller, is the debut novel of American novelist Ruta Sepetys.  It follows the Stalinist repressions of the mid-20th century and follows the life of Lina as she is deported from her native Lithuania with her mother and younger brother and the journey they take to a labor-camp in Siberia.  It was nominated for the 2012 CILIP Carnegie Medal and has been translated into more than 27 languages.

Dora Levy Mossanen: Dora Levy Mossanen (born December 28, 1945) is an American author of historical fiction.  Her published works include "Harem" (2002), "Los Angeles Times" and "Denver Post" best-seller "Courtesan" (2005), "Denver Post" best-seller "The Last Romanov" (2012), and "Denver Post" best-seller "Scent of Butterflies" (2014).  She is a graduate of the University of Southern California Masters of Professional Writing Program and is the recipient of the San Diego State University Editor's Choice Award.

Jay Papasan: Jay Papasan is an American writer and business executive.  He is best known for co-authoring, with Gary Keller, books such as "The Millionaire Real Estate Investor", which became both a New York Times best-seller and a BusinessWeek best-seller, and "The ONE Thing", which reached #1 on the Wall Street Journal business best-seller list.  Papasan is the vice president of publishing and executive editor at KellerINK, the publishing arm of Keller Williams Realty.  He and his wife Wendy are owners of "The Papasan Real Estate Team".  In 2014 he was named one of the "Most Powerful People in Real Estate" by Swanepoel Power 200.

Ruta Sepetys: Ruta Sepetys or Rūta Šepetys (born November 19, 1967) is a Lithuanian-American writer of historical fiction.  As an author, she is a #1 "New York Times" bestseller, international bestseller, and winner of the Carnegie Medal.Sepetys is a Rockefeller Foundation Bellagio Fellow and the first American writer of young adult literature to speak at European Parliament.  Her work is published in over fifty countries and thirty languages and is currently in development for two films.

Supporting paragraphs: Ashes in the Snow Between Shades of Gray
Answer: Between Shades of Gray