[1]  Liu Bolian, Lai H J. Matrices in Combinatories and Graph Theory. Dordrecht: Kluwer Press, 2000

[2]  Cao D S. Bounds on eigenvalues and chromatic number. Linear Algebra Appl, 1998, 270: 1--13

[3]  Liu Bolian. On sharp bounds of the spectral radius of graphs. Univ Beograd Publ Electrotechn, Fak Ser  Mat, 1998, 9: 55--59

[4]  Hong Y, Shu J L,  Fang K.  A sharp upperbound of the spectral radius of graphs. J Combin Theory Ser B,
2001, 81: 177--183

[5]  Favaron O, Maheo M, Sade J F. Some eigenvalue properties in graphs (conjectures of Graffiti--II). Discrete Math, 1993, 111: 197--220

[6]  Berman A, Zhang X D. On the spectral radius of graphs with cut vertices. J Combin Theory Ser B,  2001, 83: 233--240

[7]  Kinkar Ch Das, Pawan Kumar. Some new bounds on the spectral radius of graphs. Discrete Math,  2004, 281: 149--161

[8]  Stevanovi\'c D.  The largest eigenvalue of nonregular graphs.  J Combin Theory Ser B,  2004, 91: 143--146

[9]  Bondy J A,   Murty U S R. Graph Theory with Applications. London: The Macmillan Press LTD, 1976