Gollub, Erica L <br/><br/>
ECHO: context and limitations.  [electronic resource] 

 -  Lancet (London, England)  02 2020 
 - e24 p.  digital 
<br/><br/> Publication Type: Letter; Comment 
<br/><br/><label>ISSN: </label>1474-547X 
<br/><br/><label>Standard No.: </label>10.1016/S0140-6736(19)33108-3  doi 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Contraception<br/>Female<br/>HIV Infections<br/>Humans<br/>Incidence<br/>Intrauterine Devices, Copper<br/>Levonorgestrel<br/>Medroxyprogesterone Acetate