A sua pesquisa - ((communications convention) or (communications connections)) systems dimensioning databases under - não corresponde a nenhum registo.

Talvez deva tentar algumas variações de ortografia:
communications connections » communication connection, communication collections, communication connecting
communications convention » communication connection, communication conversation, communications companion
dimensioning databases » dimensional databases, designing databases, dimensional database
systems dimensioning » systems dimensions, systems designing, systems diversifying

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