"one of which" is an acceptable phrase in written English. You can use it to refer to one of several things in a prior sentence. For example: "I visited many cities during my holiday, one of which was Rome.".
One of which is catching on in central London, too.
One of which is the Lake/Flato project in Texas featured on the cover.
The attacker had two grenades, one of which he exploded.
One of which was that of Claudette Meek.
JUSTICE SCALIA -- One of which could be a manual recount.
One of which is the power of symbolism.
I stopped doing all the things I loved--one of which, was creating.
I love the desktop app, it’s always running on my Mac. Ludwig is the best English buddy, it answers my 100 queries per day and stays cool.
Cristina Valenza
Retail Lead Linguist @ Apple Inc.