Location and abundance of poly (A) sequences in Sendai virus messenger RNA molecules -- Marx et al. 27 (2): 247 -- Journal of General Virology

Adenine-rich sequences from 18S Sendai virus messenger RNA species were 99% adenylate, 3'-OH terminal, and were present in at least 50% of the RNA molecules. Intact virus messenger RNA molecules were resistant to exonucleolytic attack by polynucleotide phosphorylase, suggesting that their 3'-termini are masked.