April Ryan, veteran journalist, host and Washington Bureau Chief for American Urban Radio Networks (AURN), discusses her latest book, "At Mama’s Knee: Mothers and Race in Black and White." Dava Sobel discusses her latest book "The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars." Graeme Wood, a national correspondent for The Atlantic, joins us to discuss his book, "The Way of the Strangers: Encounters with the Islamic State."