参考资料:
1. Sinha M, Rani R, Gupta R, Chand K, Kaur G. Lippes Loop Inserted 45 Years Back: The Dilemma to Remove It or Leave It in Situ. A Case Report with Review of Literature. J Clin Diagn Res. 2015;9(4)E01-5. doi:10.7860/JCDR/2015/12981.5832 - Pubmed