'A'
Efficient path protection in bi-directional WDM systems
Author(s): Li J (Li, Ji), Yeung KL (Yeung, Kwan L.), Chan CK (Chan, Chun-Kit)  
Source: COMPUTER NETWORKS    Volume: 52    Issue: 6    Pages: 1166-1178    Published: APR 24 2008  
Authors' addresses:
Univ Hong Kong, Dept Elect & Elect Engn, Pokfulam, Hong Kong Peoples R China
Chinese Univ Hong Kong, Dept Informat Engn, Shatin, Hong Kong Peoples R China

'B'
Bidirectional wavelength add-drop multiplexer using multiport optical circulators and fiber Bragg gratings
Author(s): Kim J, Lee B  
Source: IEEE PHOTONICS TECHNOLOGY LETTERS    Volume: 12    Issue: 5    Pages: 561-563    Published: MAY 2000