Existence of vigorous lineages of crop-wild hybrids in Lettuce under field conditionsDanny A.P. Hooftman, Yorike Hartman, J. Gerard B. Oostermeijer and Hans (J.) C.M. Den NijsEnviron. Biosafety Res., 8 4 (2009) 203-217DOI: https://doi.org/10.1051/ebr/2010001