//-->
Sampling strategies, robustness and efficiency : the state of the art
Iachan, Ronaldo, (1984)
On unequal probability sampling : a review
Basu, D., (1977)
Some sources of nonsampling errors in African census and survey work : a review
Kiregyera, Ben, (1982)
A family of differentiation indices
Plane sampling
Iachan, Ronaldo, (1985)