'A' cited 'B'.

'A'
Intersubband transitions in InGaAsN/GaAs quantum wells
Author(s): Liu W (Liu, W.)1, Zhang DH (Zhang, D. H.)1, Fan WJ (Fan, W. J.)1, Hou XY (Hou, X. Y.)2, Jiang ZM (Jiang, Z. M.)2  
Source: JOURNAL OF APPLIED PHYSICS    Volume: 104    Issue: 5  Article Number: 053119    Published: SEP 1 2008    
Authors' addresses:
1. Nanyang Technol Univ, Sch Elect & Elect Engn, Singapore 639798, Singapore
2. Fudan Univ, Dept Phys, Shanghai, Peoples R China

'B'
Modeling of intersubband and free-carrier absorption coefficients in heavily doped conduction-band quantum-well structures
Author(s): Kim KY, Lee B, Lee C  
Source: IEEE JOURNAL OF QUANTUM ELECTRONICS    Volume: 35    Issue: 10    Pages: 1491-1501    Published: OCT 1999