Treatises, Restatements, and Law Review Articles are considered strong secondary sources in legal research. They provide in-depth analysis and commentary on legal principles and are widely cited in legal arguments.
| I | Hypothesis | a | Null |
| II | published Books | b | Tool |
| III | Schedule | c | Subject matter of research |
| IV | Applied | d | Secondary Source |
| I | Hypothesis | a | Null |
| II | published Books | b | Tool |
| III | Schedule | c | Subject matter of research |
| IV | Applied | d | Secondary Source |