I need a human translation from a native speaker for the English to Spanish exercise book on Public Economics. To complete the task, I will provide a latex code in English and ask you only to translate the text and *let the commands and math content intact*. A considerable part of the text is about math derivations and figures that do not demand translation. Delivery dates can be flexible within February and April and arranged in anticipation. The first delivery is on Feb 15th. I need the freelancer to produce an invoice with specific information.