Gaya APA
Marini, L, F. (2013).
Trajectory Of Directional Drilling .
UPT Perpustakaan UP 45:
Universitas Proklamasi 45.
Gaya MLA
Marini, Lion, Ferdinand.
"Trajectory Of Directional Drilling".
UPT Perpustakaan UP 45:
Universitas Proklamasi 45,
2013.
Seminar TP.