Wark, Peter A. B., Hew, Mark, Xu, Yang, Ghisla, Clare, Nguyen, Tra-My, Erdemli, Bora, Samant, Aditya, Nan, Cassandra. Taylor & Francis Inc.; 2023. Regional variation in prevalence of difficult-to-treat asthma and oral corticosteroid use for patients in Australia: heat map analysis.