APA
World Health Organization, . (1997). Determination of airborne fibre number concentrations : a recommended method, by phase - contrast optical microscopy (membrane filter method). auth., Geneva: .
Chicago
World Health Organization, . 1997. Determination of airborne fibre number concentrations : a recommended method, by phase - contrast optical microscopy (membrane filter method). auth., Geneva: .
Harvard
World Health Organization, . (1997). Determination of airborne fibre number concentrations : a recommended method, by phase - contrast optical microscopy (membrane filter method). auth., Geneva: .
MLA
World Health Organization, . Determination of airborne fibre number concentrations : a recommended method, by phase - contrast optical microscopy (membrane filter method). auth., Geneva: . 1997.