A nature can be retrospective.Logical formLearned from83 sentences. Reviews can be retrospective.Logical formLearned from79 sentences. A survey can be retrospective.Logical formLearned from72 sentences. Reports can be retrospective.Logical formLearned from71 sentences. Materials can be retrospective.Logical formLearned from62 sentences. A system can be retrospective.Logical formLearned from58 sentences. Studies can be retrospective.Logical formLearned from56 sentences. A basis can be retrospective.Logical formLearned from55 sentences. An evaluation can be retrospective.Logical formLearned from55 sentences. Interviews can be retrospective.Logical formLearned from49 sentences. A book can be retrospective.Logical formLearned from49 sentences. An article can be retrospective.Logical formLearned from45 sentences. A retrospective study can be constituted-of-or-filled-with some patients.Logical formLearned from44 sentences. An assessment can be retrospective.Logical formLearned from43 sentences. A cd can be retrospective.Logical formLearned from40 sentences.