Title:System requirements engineering by V. Loucopoulos and V. Karakostas : 1995.- McGraw-Hill International series in Software Engineering. ISBN 0-07-707843-8
Title:Practical software measurement. Objective information for decision makers : J. McGary, D. Card, C. Jones, B. Layman, W. Clark, J. Dean, F. Hall Addison-Wesley 2002, 2002