Convert bams to vcf files

Hi,

I have bam files downloaded from the 1000 Genomes Project and I need to have fasta files as the reference files (for -R option) in order to turn my bams into vcf files. Can you please tell me where to find fasta files from for my data? I tried using samtools and picard, but I don't really know where to get files to convert them to fasta..

Thank you!