Radoslav Dimitric was the first to give a complete characterization of slender objects in the general setting of Abelian categories. His research has mostly been concerned with algebra and how it relates to topology and set theory, but his research also includes the history of mathematics, mathematics education and financial engineering.
'At the end of every chapter some exercises, problems and notes are gathered which could be very useful for understanding the theory and for future research on this subject.' George Ciprian Modoi, MathSciNet 'At the end of every chapter some exercises, problems and notes are gathered which could be very useful for understanding the theory and for future research on this subject.' George Ciprian Modoi, MathSciNet