From: Rabbi Moshe Sofer
To: Unknown recipient
When a city has only one esrog available and the local authority rules the shaliach tzibbur can take the lulav on behalf of the entire congregation, the Chasam Sofer disagrees. He demonstrates that the Torah's requirement of 'ulekachtem' mandates individual taking as an independent obligation.
Source: Shu"t Chasam Sofer OC §182