You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A survey of combinatorial testing 
Chapter Title:  A.4. Grindal et al. 
1. Abstract of Cited Paper (BIB001):  This study compares seven different methods for handling constraints in input parameter models when using combination strategies to select test cases. Combination strategies are used to select test ... 
2. Abstract of Cited Paper (BIB002):  Combination strategies are test methods that generate test cases based on input parameter models. This paper suggests a structured modeling method used to translate requirements expressed in a general format into an input parameter model suitable for combination strategies. ::: ::: This paper also describes results from two initial experiments exploring the efficiency and effectiveness of the modeling method. These results indicate that the resulting models may contain enough information to detect the vast majority of faults in the system under test. Further, results indicate that the modeling method is simple enough to use in practical testing.

Literature Review:
Grindal et al. studied modeling of SUT, test generation, application, constraints solving, and evaluation. They surveyed 15 different combination strategies extracted from more than 30 related papers, reviewed almost all of the published papers in this field before 2004, and gave a subsumption hierarchy to relate the various coverage criteria associated with the identified combination strategies BIB001 . They presented four different methods for handling constraints in parameter models when using combination strategies to select test cases, and compared them to three existing methods BIB002 ]. They also presented results from a comparative evaluation of five combination strategies, and evaluated them with respect to the number of test cases, the number of faults found, failure size, and the number of decisions covered  . Recently, they presented an eight-step structured method for the creation of input parameter models custom-designed for combination strategies BIB003 .