Narrow spectrum tetracycline for moderate-to-severe acne | Dermatology Times
https://www.dermatologytimes.com/acne/narrow-spectrum-tetracycline-moderate-severe-acne
Sarecycline: a narrow spectrum tetracycline for the treatment of moderate-to-severe acne vulgaris
https://www.futuremedicine.com/doi/10.2217/fmb-2019-0199