Official websites use .gov
Secure .gov websites use HTTPS
Authors
- Agassiz, Louis, 1807-18731
- Agassiz, Louis, 1807-1873 author1
- Agboola, Foluso, author5
- Agg, John, 1783-18551
- Agnew, D. Hayes (David Hayes), 1818-18925
- Aikin, John, 1747-18223
- Aikin, William E. A., 1807-18881
- Air University (U.S.). Arctic, Desert, and Tropic Information Center, author.1
- Aitken, William, 1825-18922
- Akerly, Samuel, 1785-18451
- Alabama. State Department of Health, author.1
- Alaska. Department of Health, author.1
- Alberta.1
- Alcott, William A. (William Andrus), 1798-185913
- Alcott, William A. (William Andrus), 1798-1859 author1
- Alexander, Leo, 1905-1985 author1
- Alibert, Jean-Louis-Marie, 1768-18371
- Allbutt, T. Clifford (Thomas Clifford), 1836-19251
- Allen, Alfred Henry, 1847-1904 author4
- Allen, Charles Warrenne, 1854-19061