A Name on the Wall - SI Vault
"Bob Kalsu had just finished a stellar rookie year in the NFL when he chose to serve in Vietnam - and became the only U.S. pro athlete to die there."

Memorial Day's honor belongs to fallen heroes like former Bills lineman Robert Kalsu - Palm Beach Post
Bob Kalsu's son, Robert Jr., discusses the father he never knew. Kalsu follows the Buffalo Bills religiously, and talks about his dad's name on the Wall of Fame.

Remembering Five Athletes Who Died While Serving Their Country - Forbes
Kalsu is among a handful of professional athletes who gave their lives for the United States since World War I.

Memorial Day Tribute: James Robert Kalsu, Sr. - True North
Bob Kalsu's daughter responded to a letter from Brad Carlson of the Minnesota political blog True North.

Remembering those who served is what today is all about - themorningsun.com
"Although not nearly as well known, Bob Kalsu, a linebacker for the Buffalo Bills, was killed in Vietnam in 1970. He was in the ROTC program at the University of Oklahoma, and was called to active duty following his first season in the NFL."

This Day in Buffalo Sports History: A tragic anniversary - The Buffalo News
"July 21, 1970 - It's one of the saddest days in Buffalo Bills' history, as offensive lineman Bob Kalsu dies when he is hit by mortar fire in Vietnam's Ashua Valley."

Inside The Bills | Kalsu: The whole story
"Kalsu was the Sports Illustrated cover story back in 2001 and the nine page write up is a must for any Bills fan."