Prime Archives in Public Health Substitution of Formal and Informal Healthcare among Retired Population Implication for Social and Public Health PolicyDownload Substitution-of-Formal-and-Informal-Healthcare-among-Retired-Population-Implication-for-Social-and-Public-Health-Policy Share: Newer Post Adults Experiencing Homelessness in the US–Mexico Border Region: A Photovoice Project Older Post The Practice of Extended “Like Dissolves Like” Rule in the Ultrasonic Extraction of Tropane Alkaloids from Radix Physochlainae by Using Ionic Liquids with Similar Structure