That leaves scientists with neural stem cells -- a source of which is human embryos.
One example is recycled polyethylene, a primary source of which is recycled water bottles.
He carried with him a degree of emotional scar tissue, the source of which might only be guessed at.
The word, the source of which is obscure, seems to have originated in the late or mid-16th century.
Broadly speaking, "Eminent Domain" is a series of responses to change in the city (the source of which might be anything from gentrification to globalization).
They may be treated with a minute amount of a digestive enzyme, trypsin — one source of which is pig pancreas, which could account for the pork rumor.
This story seems to me to illustrate a side, at least, of Jane Bown's genius, the source of which she never properly understood herself and about which she remained gracefully modest.
As Batman and Superman enter the labs, the pair find that a lot of the way ahead is doused in green kryptonite rays, the source of which Batman needs to find and disable.
The IISS is full of people who should know a thing or two about "black propaganda" – forged or altered information, the source of which is masked, in order to advance policy objectives.
An insufficient number of police were deployed to Mare Street and Clarence Road, offering futile attempts to contain the anger of a vast number of youths, the source of which remains unknown.
Over the next three hours, a dozen different pies slid on and off of Mr. Varasano's peel, including a surprising arugula with lemon juice, a terrific clam pizza and a pie with oregano, black pepper and an elusive tanginess (the source of which was kept secret).
