The Tongjian gangmu qianbian 通鑒綱目前編 "Backward-continuation to the Outlines and Details of the Comprehensive Mirror" is a continuation of Zhu Xi's Tongjian gangmu 通鑒綱目. There are two books of this title, one written by the Ming period 明 (1368-1644) scholar Nan Xuan 南軒, and one by his contemporarian Xu Gao 許誥.
Nan Xuan, courtesy name Nan Shuhou 南叔后, came from Weinan 渭南, Shaanxi, and was assistant administration commissioner (canyi 參議) in Shandong. He has written a history of literature in the region of Xi'an, the Guanzhong wenxian zhi 關中文獻志. His 25 juan "scrolls" long Tongjian gangmu qianbian is a restructuring of Jin Lüxiang's 金履祥 Zizhi tongjian qianbian 資治通鑒前編 and Cheng Sheng's 陳檉 Zizhi tongjian xubian 資治通鑒續編 according to the principles of the gangmu, providing a general outline of history (gang 綱 "ropes") that is critically commented (mu 目 "meshes"). His history begins in mythical times and reaches down to the time or King Weilie 威烈王 (r. 425-402 BCE) of the Zhou dynasty 周 (11th cent.-221 BCE). Yet Nan Yuan did not strictly follow the gangmu principle so that the text of his book is not very well structured. His sources are sometimes also not correctly indicated, like quotations from the Erya 爾雅 or Zuozhuan 左傳 that are in fact taken from various encyclopedias. He also quotes Jin Lüxiang's teacher Wang Bo 王柏 with the title of Zi Bozi 子王子 "My master Bo", which should not have been done by a third person. His book is therefore not included in the collectaneum Siku quanshu 四庫全書.
Xu Hao, courtesy name Xu Tinglun 許廷綸, style Hangu shanren 函谷山人, came from Lingbao 靈寶, Henan, and was Minister of Revenue (hubu shangshu 戶部尚書) in Nanjing. His 3 juan long book was written as a better alternative to Jin Lüxiang's Zizhi tongjian qianbian that included a lot of errors. Yet instead of adhering to Zhu Xi's principle of the guidelines and commentaries, he imitated the style of the Confucian Classic Chunqiu 春秋 "Spring and Autumn Annals" and produced a book that laid too much stress on literary quality and the wording instead of the content. It is likewise not included in the collectaneum Siku quanshu.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, vol. 1, p. 902. Changchun: Jilin daxue chubanshe.