1. Human sperm head morphometric distribution and its influence on human fertility 
Nabil Aziz, Simon Fear, B.Sc., Clare Taylor, Ph.D., Charles R Kingsland, M.D., D.Iwan Lewis-Jones, M.D. 
Fertility and Sterility 
Volume 70, Issue 5, Pages (November 1998)
DOI: /S (98)

2. FIGURE 1
Distribution of sperm head area in semen and sperm preparation.
Fertility and Sterility  , DOI: ( /S (98) )

3. FIGURE 2
Distribution of sperm head area in sperm preparations in the fertilizers and nonfertilizers.
Fertility and Sterility  , DOI: ( /S (98) )

4. FIGURE 3
Distribution of sperm head area in the semen of natural fathers and men in unexplained infertile relationships.
Fertility and Sterility  , DOI: ( /S (98) )