What does PTB stand for?
PTB stands for "Permian Triassic Boundary"
How to abbreviate "Permian Triassic Boundary"?
"Permian Triassic Boundary" can be abbreviated as PTB
What is the meaning of PTB abbreviation?
The meaning of PTB abbreviation is "Permian Triassic Boundary"
What does PTB mean?
PTB as abbreviation means "Permian Triassic Boundary"
