According to the White House, one of three books Bush chose to read on his five-week vacation is "Salt: A World History" by Mark Kurlansky, who chronicled the rise and fall of what once was considered the world's most strategic commodity. The other two books he reportedly brought to Crawford are "Alexander II: The Last Great Tsar" by Edvard Radzinsky and "The Great Influenza: The Epic Story of the Deadliest Plague in History" by John M. Barry.

Bush, a former oil company chief, has not said why he picked Kurlansky's 484-page saga. "The president enjoys reading and learning about history," White House spokeswoman Dana Perino said.

Kurlansky said he was surprised to hear that Bush had taken his book to the ranch: "My first reaction was, 'Oh, he reads books?' "

The author said he was a "virulent Bush opponent" who had given speeches denouncing the war in Iraq.

"What I find fascinating, and it's probably a positive thing about the White House, is they don't seem to do any research about the writers when they pick the books," Kurlansky said.

Barry, author of "The Great Influenza," said that he too had been a Bush critic. But his views have not deterred the administration from seeking his advice on the potential for another pandemic like the 1918 outbreak that claimed millions of lives worldwide.

Although Barry was not aware that the president planned to read the book, he said he had been consulting off and on with senior administration officials since its release in February 2004. He had lunch with Health and Human Services Secretary Mike Leavitt two weeks ago.

The administration, Barry said, was investigating what steps public officials could take to lessen the severity of a flu pandemic. A central theme of Barry's book is that the 1918 outbreak was exacerbated in America by the government's attempts to minimize its significance, partly to avoid undermining efforts to prevail in World War I.

"One lesson is to absolutely take it seriously," Barry said. "I'm not a great fan of the Bush administration, but I think they are doing that. The Clinton administration I don't think paid much attention to it as a threat."

Bush's choice of "Alexander II" appears to reflect his interest in books about transformational political leaders. Among those he has perused since becoming president are biographies of George Washington, John Adams, Alexander Hamilton, Theodore Roosevelt, Richard the Lionheart and Peter the Great.