Sources

1) Source: Deeds of St. Thomas Priory, Stafford "1. Robert son of John de Ferrers lord of Certeleye"Dated: 17 Oct. 1348. Reference: D938/22 (Data from direct source)
2) Source: Chancery: Inquisitions Post Mortem, Series I, Edward III "John de Bures...held for his life of the inheritance of John son and heir of Robert de Ferrers...He died on 21 December last. Katharine his daughter, wife of Giles de Bello Campo, aged 26 years and more, is his heir...He died on the feast of St. Thomas the Apostle last. Heir as above, aged 35 years and more...He died on 21 December last. Heir as above, aged 30 years and more...He died on 6 December...John son of Robert de Ferrar’, aged 19 years, is heir of the said Hawise de Ferres."Dated: December 1350. External Link
http://discovery.nationalarchives.gov.uk/details/r/C9777688. Reference: C 135/110/8
3) Source: Exchequer: King's Remembrancer: Ancient Deeds, Series D "John de Bures and Hawise his wife to Giles de Bello Campo and Katherine his wife"Dated: 1329. External Link
http://discovery.nationalarchives.gov.uk/details/r/C5905380. Reference: E 210/9496 (Data from secondary evidence)
4) Source: Chancery: Inquisitions Post Mortem, Series I, Edward III "John de Bures...held for his life of the inheritance of John son and heir of Robert de Ferrers...He died on 21 December last. Katharine his daughter, wife of Giles de Bello Campo, aged 26 years and more, is his heir...He died on the feast of St. Thomas the Apostle last. Heir as above, aged 35 years and more...He died on 21 December last. Heir as above, aged 30 years and more...He died on 6 December...John son of Robert de Ferrar’, aged 19 years, is heir of the said Hawise de Ferres."Dated: December 1350 Evidences her children and her two marriages.. External Link
http://discovery.nationalarchives.gov.uk/details/r/C9777688. Reference: C 135/110/8 (Data from direct source)
5) Source: Chancery: Inquisitions Post Mortem, Series I, Edward I "Robert de Mucegros alias de Muscegros, de Micegros, de Muchegros...the same Robert died about fifteen days before Christmas...Hawis his daughter, aged 4 at the feast of St. Thomas [the Apostle] next before Christmas last, is his next heir."Dated: December 1280. External Link
https://www.british-history.ac.uk/inquis-post-mortem/vol2/pp230-238. Reference: C 133/28/8 (Data from direct source)
6) Source: Special Collections: Ancient Petitions "Ralph Bygot requests that the king order the justices to come to judgment in his case against Robert de Ferrers, his wife Margaret and John, son of Walter le Poure, regarding the manor of Bugbrooke."Dated: c1330. Reference: SC 8/181/9033 (Data from secondary evidence)
7) Source: Varied - Secondary Source for Medieval Genealogy "However, a Close Rolls item dated 26 October 1349 reports that "Joan late the wife of Robert de Ferrariis, John de Ferrariis, John Uphay and Nicholas Poure, executors of the will of Robert de Ferrariis, came into Chancery on 19 October and there surrendered to the king that third part of the lands which Robert held of the lands which belonged to John de Beauchamp, tenant in chief." [Reference: Calendar of Close Rolls, 1349-1354 (1906): 139]. ". Reference: Douglas Richardson; "C.P. Correction: Death date of Sir Robert de Ferrers, de jure 3rd Lord Ferrers of Chartley [died 1349]" (Data from secondary evidence)