Balanced incomplete random blocks

The design of experiment written in this form is a reconstructed Latin square design where one of the diagonals has been left out. Generally speaking, Youdens square is a symmetrically balanced incomplete random block where each factor level appears once and only once in each block position. 

Youdens square I=J=7 K=b=4 is transformed into a balanced incomplete random block for easier calculation ... 

What is the relationship - Youden square designs Latin square designs balanced incomplete block designs randomized complete block designs ... 

Consumers received 30 samples, each coded with a three-digit number, in a single session. For each subject, the 30 samples were selected from the 34 samples according to a balanced incomplete block design (BIBD). The order of presentation of the samples was randomized for each subject. 

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