Convert from cover to nook

Unit Definition (cover)
The Cover is a traditional Welsh unit of area, standardized in the British system to be exactly 2/3 acre (about 0.2698 hectare). The word is an Anglicized version of the Welsh name cyfair for the unit.

Unit Definition (nook)
The nook is a traditional unit of land area in northern England. Originally the nook was 1/2 virgate; a virgate, often called a yardland in the north, was about 30 acres in southern England but tended to be closer to 40 acres in the north. A nook of land thus came to be 20 acres or about 8.094 hectares.