1. Icnitas de Dinosaurios en Bretun;Aguirrezabala;Munibe,1980
2. Icnitas de dinosaurios en Santa Cruz de Yanguas (Soria);Aguirrezabala;Munibe,1983
3. Estimates of speeds of dinosaurs;Alexander;Nature,1976
4. Classopollis containing male cone associated with Pseudofrenelopsis;Alvin;Palaeontology,1978
5. A new coniferous male cone from the English Wealden and a discussion of pollination in the Cheirolepidiaecae;Alvin;Palaeontology,1994