The University of Nebraska-Lincoln Department of Mathematics has shirts for sale through Sept. 23, including a new long-sleeved option and a T-shirt that is also available in youth sizes.
To pick up your order in 203 Avery Hall in Lincoln, NE, starting on Oct. 5, 2018, use this link: https://pogo.undergroundshirts.com/collections/unl-math-department-apparel
To have the order shipped elsewhere, use this link: https://pogo.undergroundshirts.com/collections/unl-math-department-apparel-ship
Once the online order form closes on Sept. 23, then all orders will be processed. Orders will ship out on Oct. 5. The form will not be reopened so you must order on or before Sept. 23 at midnight EST.
http://www.math.unl.edu/friends