CURRENT ISSUE:
         Summer(2010), Vol. 51, no. 3 in PDF   chal5103.pdf

PAST ISSUES:

Spring(2010), Vol. 51, no. 2 in PDF   chall5102.pdf

Winter(2010), Vol. 51, no. 1 in PDF   chall5101.pdf

Summer(2009), Vol. 50, no. 2 in PDF   chal5002.pdf

Spring(2009), Vol. 50, no. 1 in PDF   chal5001.pdf

Winter(2009), Vol. 49, no. 3 in PDF   chal4903.pdf

Summer(2008), Vol. 49, no. 1 in PDF   chal4901.pdf (458 kb)

Spring(2008), Vol. 48, no. 4 in PDF   chal4804.pdf (808 kb)

Winter(2008), Vol. 48, no. 3 in PDF   chal4803.pdf (1.2 mb)

Autumn(2007), Vol. 48, no. 2 in PDF   chal4802.pdf (224 kb)

Summer(2007), Vol. 48. no. 1 in PDF chal4801.pdf (444 kb)

Spring(2007), Vol. 47. no. 4 in PDF chal4704.pdf (244 kb)

Winter(2007), Vol. 47, no. 3 in PDF   chal4703.pdf (213 kb)

Autumn(2006), Vol. 47, no. 2 in PDF   chal4702.pdf (296 kb)

Autumn(2004), Vol. 46, no. 2 in PDF   chal4602.pdf (294 kb)

Summer (2004), Vol. 46, no. 1 in PDF   chal4601.pdf (212 kb)

Spring (2004), Vol. 45, no. 4 in PDF   chal4504.pdf (289 kb)

Winter (2004), Vol. 45, no. 3 in PDF   chal4503.pdf (491 kb)

Autumn (2003), Vol. 45, no. 2 in PDF   chal4502.pdf (227 kb)

Summer (2003), Vol. 45, no. 1 in HTML and in PDF   chal4501.pdf (212 kb)

Spring (2003), Vol. 44, no. 4 in HTML (text version)   in PDF   chal4404.pdf (297 kb)

Winter (2003), Vol. 44, no. 3 in HTML (text version)  in PDF   chal4403.pdf (286 kb

Autumn (2002), Vol. 44, no. 2 in HTML (text version) n PDF   chal4402.pdf (361 kb

Summer (2002), Vol. 44, no. 1 in HTML     in PDF   chal4401.pdf (223 kb)

Spring (2002), Vol. 43, no. 4 in HTML    also in PDF   chal4304.pdf (325 kb)

Winter (2002), Vol. 43, no. 3 in HTML    also in PDF   chal4303.pdf (343 kb)

Fall (2001), Vol. 43, no. 2    in HTML     also in       in PDF   chal0110.pdf

Summer (2001), Vol. 43, no. 1    in PDF   chal0103.pdf

Winter 2001     in PDF   chal4203.pdf

Summer 2000     in PDF   chal4201.pdf

Spring 2000     in PDF   chal4104.pdf

Winter, 2000, Vol. 41, n. 3 (chal0001.htm)            PDF   chal0001.pdf

Fall, 1999, Vol. 41, n. 2 (chal9910.htm) 

Summer, 1999, Vol. 41, n. 1 (chal9907.htm)           PDF   chal9907.pdf

Spring, 1999, Vol. 40, n. 4 (chal9904.htm)           PDF   chal9904.pdf

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