Abbreviation for:
Huáng Xiànián 黃夏年, ed. Mínguó fójiào qíkān wénxiàn jíchéng 民國佛教期刊文獻集成 (Complete Collection of Republican-Era Buddhist Periodical Literature), 209 vols. Beijing: Quánguó túshūguǎn 全國圖書館, 2006.
There is also a supplement of 83 volumes. See MFQB.
The Digital Archives at Dharma Drum Buddhist College has developed and maintains a search tool for the entire collection, which covers both sets.
Here is the PDF of an essay that discusses the structure of this collection, the history of its compilation, and tips on how to use it.
Note that for the Hǎicháoyīn periodical 海潮音, a better quality reproduction can be found in the edition published in 2003 by Shànghǎi gǔjì chūbǎnshè 上海古籍出版社. This is especially true for photographs. The LC call number for this collection is BQ3.H353.