Table 4.

Highly cited documents in the subject under study, during the period between 1966 and 2022.

Ranking	Title	Year	Total Citations	Ref
1	Biodiesel from microalgae	2007	6283	[58]
2	The path forward for biofuels and biomaterials	2006	4433	[59]
3	Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review	2006	3889	[60]
4	Biodiesel production: a review	1999	3885	[61]
5	Microalgae for biodiesel production and other applications: A review	2010	3425	[62]
6	Biomass recalcitrance: Engineering plants and enzymes for biofuels production	2007	3278	[63]
7	Use of US croplands for biofuels increases greenhouse gases through emissions from land-use change	2008	3069	[64]
8	Biofuels from microalgae- A review of technologies for production, processing, and extractions of biofuels and co-products	2010	2886	[65]
9	Review of fast pyrolysis of biomass and product upgrading	2012	2880	[66]
10	Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review	2010	2696	[67]
11	Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances	2008	2606	[68]
12	Pretreatments to enhance the digestibility of lignocellulosic biomass	2009	2559	[69]
13	Land clearing and the biofuel carbon debt	2008	2513	[70]
14	Methods for Pretreatment of Lignocellulosic Biomass for efficient hydrolysis and biofuel production	2009	2368	[71]
15	Technical aspects of biodiesel production by transesterification - a review	2006	2248	[72]
16	Overview of applications of biomass fast pyrolysis oil	2004	2166	[73]
17	Biofuels (alcohols and biodiesel) applications as fuels for internal combustion engines	2007	2104	[74]
18	Liquid-phase catalytic processing of biomass-derived oxygenated hydrocarbons to fuels and chemicals	2007	1971	[75]
19	Conversion of biomass to selected chemical products	2012	1910	[76]
20	Production of first and second generation biofuels: A comprehensive review	2010	1902	[68]