Introduction has been given in Chapter 1. In Chapter 2, history of two-phase sampling and some well-known estimators along with their mean square errors and biases are given. Some regression cum ratio product estimators proposed by Hanif et al....

Identification and conservation of microorganism’s biodiversity is very important for the service of mankind. Microorganisms (Fungi and Bacteria) are conserved in living states in the form of cultures. For proper growth requirements, different techniques are essential for culturing....