Cthulhu Mythos anthology was created in 2001-07.
Cthulhu Mythos anthology has 540 pages.
The ISBN of The Spawn of Cthulhu is 0-345-02394-3.
The ISBN of Cthulhu's Reign is 978-0-7564-0616-5.
The ISBN of Cthulhu's Dark Cults is 1-56882-235-9.
The ISBN of Elsewhere - anthology - is 0958139016.
The ISBN of Dream Weavers - anthology - is 9780140262087.
The ISBN of Immortals - anthology - is 0-441-00539-X.
The ISBN of Steampunk - anthology - is 978-1-892391-75-9.
The ISBN of Ray Lynch Anthology is 0-793-55687-2.
The ISBN of Prime Evil - anthology - is 0-453-00572-1.
While there isn't a single book with the complete Cthulhu Mythos, many of H.P. Lovecraft's original works and stories from other authors that have contributed to the mythos are often collected in anthologies or omnibus editions. You may want to look for collections that include a wide range of stories related to the Cthulhu Mythos to get a comprehensive look at the universe.