Pengaruh karboksimetil selulosa (CMC) terhadap pengurangan hambatan aliran dalam pipa segitiga sama sisi 20 mm = The effect of carboxymethyl cellulose (CMC) solution on drag reduction in isosceles triangular pipe 20 mm / Ayubi Lutfianto - Ayubi Lutfianto, author (Fakultas Teknik Universitas Indonesia, 2014)