Attributed to the Bibiena Family, early 18th Century

Attributed to the Bibiena Family, early 18th Century
Five architectural studies of an elaborate palace (recto and verso) in two frames
Inscribed '7' and 'G' (1) and 'T.' (2)
pen and brown ink, grey-blue wash, watermark encircled GR below trefoil (1), on two separate sheets
11 3/8 x 8 in. (28.9 x 20.3 cm.) each (2)