Gaya APA

Napitupulu, J. (2015). An analysis of students' difficultiesin understanding present perpect tense in second semester of english departement of Riau Kepulauan University in Academic year 2014/2015 : skripsi, jurnal . : Universitas Riau Kepulauan Batam.

Gaya MLA

Napitupulu, Juliana. "An analysis of students' difficultiesin understanding present perpect tense in second semester of english departement of Riau Kepulauan University in Academic year 2014/2015 : skripsi, jurnal". : Universitas Riau Kepulauan Batam, 2015. Text.