Automorphisms of semitriangular graphs with μ = 6

citation_journal_title=Arch. Math.; citation_author=D. G. Higman; citation_volume=21; citation_publication_date=1970; citation_pages=151-156; citation_doi=10.1007/BF01220896; citation_id=CR1 citation_journal_title=Bull. London Math. Soc.; citation_author=M. W. Liebeck, J. Sax; citation_volume=18; citation_publication_date=1986; citation_pages=165-172; citation_doi=10.1112/blms/18.2.165; citation_id=CR2 citation_title=Permutation Groups; citation_publication_date=1999; citation_id=CR3; citation_author=P. Cameron; citation_publisher=Cambridge Univ. Press