- E-bookA Fertility Program for Growing Vegetables - With Information on Soil, Manures and Use of ChemicalsRalph L. Watts
- E-bookVegetable Forcing - Containing Information on Greenhouse Construction, Management and Frame CultureRalph L. Watts
- E-bookLivestock and Animal Products in the Tropics - Containing Information on Zebu, Cattle, Swine, Buffalo and Other Tropical LivestockRalph L. Watts