On the iteration of polynomials of degree 4 with real coefficients

P Bhattacharyya, Y. E. Arumaraj
1981 Annales Academiae Scientiarum Fennicae Series A I Mathematica  
doi:10.5186/aasfm.1981.0605 fatcat:y3pzwmzohjh4lfiw44p7kc3pmq