
| Effect of Assortative Mating and Family Planning of the Incidence of Unisexsual Sibships |
| Interrelation between Paternal Age and the Human Sex Ratio. A Confirmation of Novitski's Theorem |
| Is there a Relation between the Dichotomy of Aging and the Dichotomy of the Human Sex Ratio? |
| Sex Distribution in Sibships According to Occupation of Parents |