A library system is a central organization created to manage and coordinate operations and services in or between different centers, buildings or libraries branches and library patrons.
 They use a library classification to organize their volumes and nowadays also use an Integrated library system - an enterprise resource planning system for a library used to track items owned, orders made, bills paid, and patrons who have borrowed.
 Many counties, states and universities have developed their own library systems.
 For example, the London Public Library in Canada has 16 branches, and the Helsinki Metropolitan Area Libraries, in Finland, has 63 libraries.
 Some countries, such as Venezuela, have only one library system for the whole country; the National Library of Venezuela has 685 branches.
The Tampa–Hillsborough County Public Library System (THPL) is a public library system based in Hillsborough County, Florida.
 The State Library of Florida is the main library source for Government of Florida as well as governs a large portion of Florida's public and private libraries.
 THPL is part of two larger library networks, the Hillsborough County Public Library Cooperative and the Tampa Bay Library Consortium, which also includes Temple Terrace Public Library in Temple Terrace, Florida, and Bruton Memorial Library in Plant City, Florida.
 There are 25 branches of the Tampa–Hillsborough County Library System, not including digital-only and mobile-only services.
 Services provided by the THPL include (but are in no way limited to) internet access, public meeting room spaces, interlibrary loans, a Bookmobile, a Cybermobile for Spanish speakers, technology classes, adult literacy programs, and downloadable eBooks.
 Drive-thru windows for returns and hold pick-ups are located at the Jimmie B. Keel and the Jan Kaminis Platt Regional Libraries.
 The Tampa–Hillsborough County Public Library System is also a part of Hillsborough County government.
The Detroit Public Library is the largest library system in the U.S. state of Michigan by volumes held (after the University of Michigan Library) and is the 21st largest library system (and the fourth-largest public library system) in the United States.
 It is composed of the Main Library on Woodward Avenue, which houses the library's administration offices, and 23 branch locations across the city.
 The Main Library is part of Detroit's Cultural Center Historic District listed in the National Register of Historic Places adjacent to Wayne State University campus and across from the Detroit Institute of Arts.
Inanna Publications and Education Inc. is a Canadian book publisher based in Toronto, Ontario.
 Inanna publishes women's writing, including a journal, literary fiction, poetry, and academic books.
 Inanna's books are on a wide variety of feminist topics accessible to the largest possible community of women.
 Inanna "is bucking the trend – and flourishing."
 Most of Inanna Publications' books are collected at Harvard Library.
 Inanna's writers have won several Independent Publisher Book Awards and Canadian Jewish Book Awards, and have been shortlisted for the League of Canadian Poets's Raymond Souster Award, the Western Mail (Wales) Book of the Year, the Lambda Literary Foundation awards, and have been among the Toronto Book Award finalists.
Atlantic County Library System is the county library system of Atlantic County, New Jersey.
 The library system is the information center in Atlantic County.
 The Library System includes nine branch libraries located throughout Atlantic County: Brigantine, Egg Harbor City, Egg Harbor Township, Galloway Township, Hammonton, Mays Landing, Pleasantville, Somers Point, and Ventnor.
 The computerized public access catalog contains over 500,000 books, audio-visual and downloadable items.
 Atlantic County Library System also has a bookmobile, books-by-mail, and other outreach services.
Toronto Public Library (TPL) (French: "Bibliothèque publique de Toronto" ) is a public library system in Toronto, Ontario.
 It is the largest public library system in Canada and in 2008, had averaged a higher circulation per capita than any other public library system internationally, making it the largest neighbourhood-based library system in the world.
 Within North America, it also had the highest circulation and visitors when compared to other large urban systems.
 Established as the library of the Mechanics' Institute in 1830, the Toronto Public Library now consists of 100 branch libraries and has over 12 million items in its collection.
The Harvard Library system comprises about 73 libraries, with more than 18 million volumes.
 It is the oldest library system in the United States and the largest university library and largest private library system in the world.
 Based on number of items held (including musical scores, maps, prints, recordings, etc.), it is the fifth largest library in the United States; based only on volumes (generally books), it is the third largest, after the Library of Congress and Boston Public Library.
The Reaching Across Illinois Library System is a regional library system consisting of 1,300 public, academic, special, and school library members, representing more than 3,500 library facilities in Northern Illinois.
 The regional library system was created in 2011 when the Alliance Library System, DuPage Library System, Metropolitan Library System, North Suburban Library System, and Prairie Area Library System merged.
The Metropolitan Library System (MLS) was an association of academic, public, school, and special libraries in Chicago and its suburbs in Cook, DuPage and Will counties.
 On July 1, 2011, Metropolitan Library System merged with Alliance Library System, DuPage Library System, North Suburban Library System, and Prairie Area Library System to form the Reaching Across Illinois Library System.
 Sarah Ann Long, director of the North Suburban Library System, summarized the evolution of organizations in northern Illinois in a 2011 essay,"Context is Everything."
The St. Petersburg Library System is a free public library system for residents of the city of St. Petersburg, Florida, located in Pinellas County.
 The St. Petersburg Library System is part of the Pinellas Public Library Cooperative and consists of 7 branch locations.
 The mission of the St. Petersburg Library System is to "provide library resources to meet educational, recreational, cultural, intellectual and social needs of our diverse community".

Question: Inanna Publications have books collected at the library system with more than how many volumes?
Answer: 18 million