<｜begin▁of▁sentence｜>### Instruction:
Given a graph of publications which you can read from publications.gml, can you use the bibcoupling function in igraph to calculate bibliographic coupling scores for all vertices (publications) and display the resulting coupling matrix?
### Response:
import igraph as ig

# Load graph data
G = ig.read('publications.gml')

# Calculate bibliographic coupling
bib_coupling_matrix = G.bibcoupling()

# Print bibliographic coupling matrix
print(bib_coupling_matrix)
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