- Cărți electroniceSeed DispersalW. J. (William James) Beal
- Cărți electroniceSeeds of Michigan Weeds Bulletin 260, Michigan State Agricultural College Experiment Station, Division of Botany, March, 1910W. J. (William James) Beal
- Cărți electroniceSeeds of Michigan Weeds Bulletin 260, Michigan State Agricultural College Experiment Station, Division of Botany, March, 1910W. J. (William James) Beal