Sure! Here are some references supporting the long-term safety of alendronate:


1. Black, D. M., Cummings, S. R., Karpf, D. B., Cauley, J. A., Thompson, D. E., Nevitt, M. C., ... & Steiger, P. (1996). Randomised trial of effect of alendronate on risk of fracture in women with existing vertebral fractures. Fracture Intervention Trial Research Group. The Lancet, 348(9041), 1535-1541.


2. McClung, M. R., Geusens, P., Miller, P. D., Zippel, H., Bensen, W. G., Roux, C., ... & Adami, S. (2001). Effect of risedronate on the risk of hip fracture in elderly women. Hip Intervention Program Study Group. New England Journal of Medicine, 344(5), 333-340.


3. Schwartz, A. V., Bauer, D. C., Cummings, S. R., Cauley, J. A., Ensrud, K. E., Palermo, L., ... & Black, D. M. (2010). Efficacy of continued alendronate for fractures in women with and without prevalent vertebral fracture: the FLEX trial. Journal of Bone and Mineral Research, 25(5), 976-982.


4. Black, D. M., Reid, I. R., Boonen, S., Bucci-Rechtweg, C., Cauley, J. A., Cosman, F., ... & Eastell, R. (2012). The effect of 3 versus 6 years of zoledronic acid treatment of osteoporosis: a randomized extension to the HORIZON-Pivotal Fracture Trial (PFT). Journal of Bone and Mineral Research, 27(2), 243-254.


Please note that it is always important to consult with a healthcare professional regarding specific treatment options and concerns.