I'm currently doing some work on Phoebe, mentioned in Romans 16:1-2. Here's the passage in Greek with my translation:
Συνίστημι δὲ ὑμῖν Φοίβην τὴν ἀδελφὴν ἡμῶν, οὖσαν [καὶ] διάκονον τῆς ἐκκλησίας τῆς ἐν Κεγχρεαῖς, ἵνα αὐτὴν προσδέξησθε ἐν κυρίῳ ἀξίως τῶν ἁγίων καὶ παραστῆτε αὐτῇ ἐν ᾧ ἂν ὑμῶν χρῄζῃ πράγματι· καὶ γὰρ αὐτὴ προστάτις πολλῶν ἐγενήθη καὶ ἐμοῦ αὐτοῦ.
I recommend to you Phoebe, our sister, being a minister of the church at Cenchreae, in order that you may receive her in the Lord as is fitting for the saints, and aid her in whatever she may require from you, for she has been a benefactor of many and of myself as well.
Below you will find a list of books and articles that deal specifically with Phoebe. If I've missed out anything significant, please let me know. I'm particularly interested in published works, but if there are internet articles, I'd consider them. Enjoy!
Bibliography on Phoebe
Arichea, D. C. “Who was Phoebe? Translating Diakonos in Romans 16:1”, BT 39 (1988), 401-409.
Bassler, J. M. “Phoebe”, in Carol Meyers (ed.) Women in Scripture (Grand Rapids: Eerdmans, 2000), 134-135.
Bieringer, R. “Women and Leadership in Romans 16: The Leading Roles of Phoebe, Prisca, and Junia in Early Christianity: Part I”, East Asian Pastoral Review 44 (2007), 221-237.
Campbell, J. C. Phoebe: Patron and Emissary. Paul’s Social Network: Brothers and Sisters in Faith; Minnesota: Liturgical Press, 2009.
Clarke, A. D. “Jew and Greek, Slave and Free, Male and Female: Paul’s Theology of Ethnic, Social and Gender Inclusiveness in Romans 16,” in Rome in the Bible and the Early Church, Peter Oakes (ed.) Grand Rapids: Baker Academic, 2002), 103-125.
Cotter, W. “Women’s Authority Roles in Paul’s Churches: Countercultural or Conventional” NovT 36 (1994), 350-372.
Croft, S. “Text Messages: The Ministry of Women and Romans 16”, Anvil 21 (2004), 87-94.
Ellis, E. E. “Paul and His Co-Workers”, NTS 17 (1977), 437-452.
Ellis, E. E. Paul and His Coworkers”, DPL, 183-189.
Fiorenza, E. S. “Missionaries, Apostles, Co-workers: Romans 16 and the Reconstruction of Women’s Early Christian History, WW 6 (1986), 420-433.
Goodspeed, E. J. “Phoebe’s Letter of Introduction,” HTR 44 (1951), 56-57.
Jewett, R. “Paul, Phoebe, and the Spanish Mission,” in J. Neusner, et al. (eds.). The Social World of Formative Christianity and Judaism: Essays in Tribute to Howard Clark Kee. Philadelphia: Fortress, 1988, 144-64.
Kearsley, R. A. “Women in the Public East: Iunia Theodora, Claudia Metrodora and Phoebe, Benefactress of Paul,” TynBul 50 (1999), 189-21.
MacMullen, R. “Women in Public in the Roman Empire,” Historia 29 (1980), 208-218.
Mathew, Susan. Women in the Greetings of Rom 16.1-16: A Study of Mutuality and Women's Ministry in the Letter to the Romans. LNTS. Edinburgh: T & T Clark, 2013.
Ng, E. Y. “Phoebe as Prostatis”, TJ 25 (2004), 3-13.
Osiek, C. “Diakonos and Prostatis: Women’s Patronage in Early Christianity,” HTS 61 (2005), 347-370.
Romaniuk, K. “Was Phoebe in Romans 16, 1 a Deaconess?” ZNW 81(1990), 132-34.
Schulz, R. R. “A Case for “President” Phoebe in Romans 16:2”, LTJ 24 (1990), 124-27.
Thomas, W. D. “Phoebe: A Helper of Many”, ExpTim 95 (1984), 336-337.
Trebilco, P.R. “Women as Co-workers and Leaders in Paul's Letters.” Journal of the Christian Brethren Research Fellowship 122 (1990): 27-36.
Whelan, C. F. “Amica Pauli: The Role of Phoebe in the Early Church”, JSNT 49 (1993), 67-85.