@article {CaTrTr2005,
 author="D. Caponetti, A. Trombetta and G. Trombetta",
 title={Proper $1$-ball contractive retractions in Banach spaces of measurable functions},
 journal="Bull. Austral. Math. Soc.",
 fjournal={Bulletin of the Australian Mathematical Society},
 volume="72",
 year="2005",
 number="2",
 pages="299--315",
 issn="0004-9727",
 coden="ALNBAB",
 language="English",
 date="5th May, 2005",
 classmath=" 47H09, 46E30",
 publisher={AMPAI, Australian Mathematical Society},
 MRnumber="MR2183411",
 ZBLnumber="02246392",
 url="http://www.austms.org.au/Publ/Bulletin/V72P2/722-5138-CaTrTr/index.shtml",
 acknowledgement={},
 abstract={ In this paper we consider the Wo\'sko problem of evaluating, in an infinite-dimensional Banach space $X$, the infimum of all $k \ge 1$ for which there exists a $k$-ball contractive retraction of the unit ball onto its boundary. We prove that in some classical Banach spaces the best possible value $1$ is attained. Moreover we give estimates of the lower H-measure of noncompactness of the retractions we construct. }
}