Patrick Willis to retire after 8 seasons with San Francisco 49ers - Niners Nation
49ers Alumnus Patrick Willis to Be Inducted into Bay Area Sports Hall of Fame
Patrick Willis of San Francisco 49ers to announce retirement - ESPN
49ers linebacker Patrick Willis considering retirement at 30
49ers Patrick Willis retiring after injury-shortened season
Men's San Francisco 49ers Patrick Willis Nike Scarlet Retired Alternate Game Jersey
49ers' Patrick Willis retires
Niners' Willis Decides To Call It A career
Bleacher Report - San Francisco 49ers make it official: Patrick Willis will retire. Details
Patrick Willis Explains Decision to Retire from NFL
NFL Free Agency: Patrick Willis, Justin Smith expected to retire; Colin Kaepernick on the trade block? - Field Gulls
Patrick Willis closes door on return, discusses foot issues as reason for retirement - Niners Nation
49ers hit hard after unexpected offseason departures - The Boston Globe