Drinking-water and sanitation 1981-1990  / World Health Organization  

 - Geneva:  World Health Organization,  1981 
<br/><br/> <br/> 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture
<br/><br/><label>Subjects--Index Terms: </label>Aloe vera gel 
<br/><br/><label>Universal Decimal Class. No.: </label>628.1"1981/1990"  / M1