Bart's book How Trees Work was written by Monsanto, which a agrochemical and agricultural biotechnology corporation.
Paula's Pugs are Nike and Swoosh. Nike's HQ are in Portland and Swoosh is the Nike logo name
Marge wears a Pendleton Wool shirt, whose HQ is in Portland.
Paula's socks pattern is that of the Portland International Airport's carpet, well known for people taking photos of their shoes on it.
Matt Groening grew up in Portland. Many of the characters and locations are from the Portland area, and western Oregon. Actual Portland street names are used as Simpsons character names. These Portland streets are shown in this episode:
Van Houten Ave
Portland landmarks are shown in the episode:
Portland International Airport (PDX)
White Stag sign
Paula's Pugs are Nike and Swoosh. Nike's headquarters are in the Portland area. Swoosh is the name of the Nike logo.
Marge is wearing a Pendleton Wool shirt. Pendleton Wool is headquartered in Portland, with mills located in nearby Washougal, WA and Pendelton, OR
The carpet in the Portland International Airport is well known, with travelers taking photos of their shoes on the carpet. The carpet pattern is shown on Paula's socks.