1. WHO global literature on Covid-19 database . This figure does not include studies that are in the pipeline, or commercial and consumer surveys that have also shifted to phone-based methods. Available: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/global-research-on-novel-coronavirus-2019-ncov [Accessed 12 Nov 2020].
2. Innovations for poverty action . High frequency monitoring of the COVID-19 response in Delhi. Available: https://www.poverty-action.org/recovr-study/high-frequency-monitoring-covid-19-response-delhi [Accessed 25 Feb 2020].
3. Morrow N , Mock N , Bauer JM . Knowing just in time: use cases for mobile surveys in the humanitarian world. humanitarian technology: science, systems and global impact. HumTech 2016.
4. Measuring Implementation Strength for Integrated Community Case Management in Malawi: Results from a National Cell Phone Census
5. Indian Express . Delhi police survey to improve services: 30,000 phone interviews, 2,000 home visits. Available: https://indianexpress.com/article/cities/delhi/delhi-police-survey-quality-council-phone-interviews-home-visits-5530903/ [Accessed 25 Feb 2021].