'A' cited 'B'.

'A'
Title: Stochastic optimization of conventional and holey double-clad fibres
Author(s): Dritsas I (Dritsas, I.), Sun T (Sun, T.), Grattan KTV (Grattan, K. T. V.)
Source: JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS 9 (4): 405-421 APR 2007  
Authors' address:
City Univ London, Sch Engn & Math Sci, London EC1V 0HB, England

'B'
Title: Simple and compact, all-fibre retro-reflector for cladding-pumped fibre lasers
Author(s): Jeong Y, Baek S, Nilsson I, Lee B
Source: ELECTRONICS LETTERS 42 (1): 15-16 JAN 5 2006