Evaluation of the Efficacy and Safety of Long—term Intake of a Dietary Supplement Containing Salmon Nasal Cartilage—derived Proteoglycan on Subjects with Subjective Knee Symptoms ―An Open Study― Tatsuji Takahashi and et al., 薬理と治療, 46, 1693-1706 (2018), DOI:http://dx.doi.org/