1. Some affects of prescribed burning on Jack Pine reproduction in North-eastern Minnesota;Ahlgren;Minn. Agric. Exp. Stn. Misc. Rep.,1970
2. Introduction;Ahlgren,1974
3. Leaf anatomy of Weichselia based on fusainized material;Alvin;Palaeontology,1974
4. Electron spin resonance study of pure macerals;Austen,1966
5. Biochemical alteration of exinites and the origin of some semi-fusinites;Bell;Fuel (London),1966