Though it's been nearly three years since Joan Rivers' tragic death at age 81, her close friends are still remembering the beloved comedienne and revealing what she was really like behind closed doors. In a new book — titled Joan Rivers Confidential — written by her daughter, Melissa Rivers, fans can take a look inside Joan's private world and see artifacts from the star's more than 50 years in showbiz.

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"[Joan found her bliss by] surrounding herself with beautiful things,” former Hollywood Reporter columnist and Joan's longtime friend Sue Cameron told Closer Weekly in an exclusive new interview. "What was surprising to me was how Joan saved literally everything from her earliest days in life," her friend Deborah Norville, anchor of Inside Edition, similarly said. "But [she had] a clear sense that she was a historical person, and these mementos were a part of her history."

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Joan and her daughter, Melissa.

"She loved royalty and collected things from Russia, France, and England," Cameron told Closer. "[Her collections weren't] a reminder of her success; she didn’t need to be reminded. She was always very, very grateful. Joan simply felt it was important when you become successful to celebrate it."

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Melissa's new book also showcases Joan's extensive collection of jokes that she used throughout her Hollywood career. "I don't throw any jokes away, even when they're no longer relevant," the late star once said. "She was much more organized than I was," Dick Cavett, another old friend told Closer. "It came in handy when she performed and needed a joke on a moment’s notice. I think most people would be surprised how bloody smart she was."

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Joan on The Tonight Show with Johnny Carson.

"[The book is fascinating] because it's a social commentary and we had a tremendous archive!" Melissa previously said of the project. "We decided to create a photographic journey through the 50 years of my mom’s career. It’s been pretty emotional… [but the result is a] history of the last five decades from a strong woman’s point of view." Joan Rivers Confidential is set to his bookstores on Oct. 24.