Wambai, U. S. K. (2019). A conceptual review of the challenges of effective tax collection from the informal sector in Kano, Nigeria. Institute for Management and Business Research (IMBRe), Universiti Utara Malaysia.

Wambai, Usman Sani Kofar. A Conceptual Review of the Challenges of Effective Tax Collection From the Informal Sector in Kano, Nigeria. Institute for Management and Business Research (IMBRe), Universiti Utara Malaysia, 2019.

Wambai, Usman Sani Kofar. A Conceptual Review of the Challenges of Effective Tax Collection From the Informal Sector in Kano, Nigeria. Institute for Management and Business Research (IMBRe), Universiti Utara Malaysia, 2019.