1. Silicone oil as mounting medium for pollen grains;Andersen;Danmarks Geol. Undersøgelse, IV,1960
2. Measurements as a means of identifying fossil pollen;Christensen;Danmarks Geol. Undersøgelse, IV,1946
3. Pollen Analysis;Erdtman,1943
4. Current trends in palynological research work;Erdtman;Grana Palynologica,1956